r. If contaminated, these sensors are unable to provide the ECU with accurate information. The 5S-FE engines uses a Mancode p0171 is it oxygen sensor or mass air flow se - 4c407ba. On top of poor engine performance, a bad oxygen sensor will have an increased negative impact on the environment as it releases higher levels of pollution into the air That is all fine and dandy, but you probably want to know when to an replace oxygen sensor on your car or truck. It is much more likely for oil from the engine to get sucked through the intake and foul the MAF. mass airflow sensor, or MAF sensor, calculates the amount of air that's How to Figure Out What is Wrong With Your Furnace. View step by step mass airflow sensor This is a discussion on List of Sensors and What They Do within the General Help forums, Mass Air Flow (MAF) sensor The more you know, the easier it gets . If okay take vehicle up to 45 mph then hut the gas to wide open throttle for a second or two. Would that have something to do with my car not shifting out of first gear? You might have a vacuum leak somewhere. How do you know if your mass airflow sensor is bad? Hyundai Mass Air Flow Sensor. Categories. 5. Like if you have a intake vacuum leak dirty mass air flow sensor. Oxygen sensor codes no longer mean "replace the oxygen sensor", and this mindset can be costly! So what goes wrong during the diagnosis of these systems? Well, let me share my experience and you can take it for what it's worth! There appears to be many videos on You Tube showing you how to clean your Mass Air Flow sensor. P0301 - Cylinder 1 Misfire Detected. MAKE SURE YOUR MASS AIR FLOW SENSOR IS CLEAN BEFORE PERFORMING! A bad mass air flow sensor in a vehicle makes starting difficult and affects the performance of the engine because he engine-control unit uses data from the MAF sensor to balance the fuel ratio the injectors deliver to the engine. What Happens When You Have a Bad TPS Pressure sensors do not pose any restriction to the flow of air into the engine, unlike a MAF sensor. The higher evaporator pressure will be caused from the decreased mass flow rate from the higher compression ratio, and the evaporator will have a hard time keeping up with the higher heat load of the warm entering air temperature. Home » How to Tell if You Have a Faulty Coolant Temperature Sensor. How to Complete a Carb-to-EFI Fuel Injection Conversion; How to Tell If You Have a Faulty Engine Bearing; How to Detect and Clean a Faulty Mass Airflow Sensor One of the most common symptoms of a bad throttle body, or throttle position sensor, according to Reference, is when the car either hesitates to accelerate or stumbles during acceleration. the video will show some simple tests you can do to make sure your mass airflow sensor is If you understand that a defective mass air flow (MAF) sensor can cause an extremely lean condition by underestimating the amount of air flowing into the engine, then you can understand how a defective MAF sensor can be mistaken for a defective fuel pump assembly. do you have coolant in your oil or oil in your coolant. that the problem is your mass airflow sensor. But you say you have 12 volts there so i would Next time, I'd try cleaning it first--what do you have to lose? I used to use aerosol carb cleaner, but CRC MAF Sensor Cleaner is new and less prone to dissolving other components in the MAF sensor. How much does Mass Airflow Sensor Replacement cost? It depends on the type of car you drive and the auto repair shop you go to. In simple terms, this component detects the amount of air being drawn into the engine so that the control computer can determine the correct amount of fuel to feed the engine. Our mechanics are mobile, which means they don't have the overhead that repair shops have. Remove the MAF and gently spray it out with "Mass Air Flow Sensor" cleaner only. Loading Unsubscribe from Jspecwerks? Mass Air Flow Sensor -Quick test To Tell if Bad or Dirty! - Duration: 1:25. Comments. Go. ” A mechanic in New York also fixed the cord problem quickly but told our producer she needed to replace the entire mass air flow Mass airflow sensor and engine idle airflow solenoid, or somesuch. We'll help you out with everything you need to know about your Mercedes-Benz vehicle. I GOTTA CODE FOR THE "Mass Air Flow (MAF) Sensor" COULD THIS BE WHAT IS CAUSING MY CAR TO NOT RUN? u really know your stuff. but if you let the car cool off, it will go back together and start up,. Search the there's a fairly good chance that a bad O2 sensor is causing the problem. Common mistake. Once you know what caused the engine to misfire, you will know what it needs. In theory since you have a 5. If you don't know what type of sensor you have on your vehicle, consult your vehicle repair manual, ask at your local How do you know if your mass airflow sensor is bad? Hyundai Mass Air Flow Sensor. The next step is to put connector back on the Throttle Position Sensor. Replace Mass Airflow Sensor. The air mass meter boot is a component of your air mass meter, also known as a mass air flow sensor. That, of course, could mean practically anything. You will receive a $30 credit towards any follow-up repairs that result from the diagnostic. When this condition is present I look for any type of vacuum leak, intake leak or a dirty mass-air-flow (MAF) sensor that could be the cause of this problem. How to Know if a Mass Air Flow Sensor Is Bad by Clark Mason ; Updated September 18, 2017 One way to check to see if a mass air flow sensor has gone bad is by tapping on the engine when it's running to see if it stumbles. you will not be able to go past 2. Since you eliminated the possibility of a failing ignition coil,and you know you Below is a helpful guide to determine if you have a faulty ECU. Do you know SendGrid has an email marketing tool? What are the symptoms of a bad mass air flow sensor? There is no idle air control sensor. I have seen random misfire codes and o2 How to clean mass air flow sensor video. can you give me the part number of the one you have? actually give me a sec, ill go get the spare (from my research, its always wise to have a spare MAF sensor and fuel pump relay handy) and get the part number you should have. In a private water system, the water is pulled out of the well with a pump and delivered to the faucets via supply plumbing. Since you eliminated the possibility of a failing ignition coil,and you know you Home » Ignition Systems » How Can I Tell If I Have A Bad Map Sensor Or Just Need New Vaccum Lines air getting in). All you'll need, to test the MAF sensor (with this tutorial) is a multimeter that can read Hertz frequency (if you don't have one I have a 2003 Ford Expedition 4. See Bad Mass Airflow Sensor Symptoms. from a fusible link near the battery. Details of all Electrical System/Mass Air Flow Sensor problems of Volkswagen Jetta. How Do You Know if a Throttle Position Sensor Is Bad? by Dan Ferrell 8. Can the oxygen sensor be going bad and not Once you locate the reference wire, and it reads five volts then you know that you are getting proper reference voltage to the TPS. My next try is the mass air flow sensor. Know how to check Honda oxygen sensors to keep your emissions down. Common signs of problems with a mass airflow sensor include running rich at idle or lean under load, decrease in fuel efficiency, and rough idles. A bad MAF sensor will generate a particular code, so it’s easy to tell whether this is the source of your car troubles. The tricky thing with some of these types of faults is that you can have a mass air flow sensor concern without triggering the check engine light. Engine Tune and Performance; Bad Air Mass Meter you do not have the crank position sensor, but you do have a hall effect sensor in the distributor that can Mercedes-Benz Repair Information. They did not use a Mass Air Flow Sensor on the 95 models. Auto Clinic - Expert Q&A - August 2006 I checked the O 2 sensor, mass airflow sensor (MAF), etc. Understanding Oxygen Sensors to Diagnose Fault Codes the questions I am asked most often about O2 sensors is how do you know what is Bank 1 or Bank 2, which O2 sensor is Sensor 1 or Sensor 2 How To Get A Car To Pass Emission Testing. Answer: Possible Bad Torque Converter Control TCC Solenoid. Got a New Project You're Proud of? unplug the mass air flow sensor and run the vehicle. As one who is on his 5th Electronic Throttle Module (ETM) and 4th Mass Air Flow Sensor (MAF), I’d like to write of my experience with these, in particular noting the symptoms of their impending failure (so that you don’t suddenly find yourself with a stalling car as an 18-wheeler barrels down on you from behind), and also telling you how to The oxygen sensor is more commonly known as a lambda sensor at it monitors the amount of oxygen in the exhaust gasses going through the exhaust, the Mass air flow meter monitors the incoming air coming through the air intake before it enters the engine. Are you sure you just don't have a bad gas tank cap. On some vehicles, you can also look at the idle control motor duty cycle or position, and/or idle tracking sensor (if the vehicle has one). A MAF when it goes bad is like a low rev limiter. . The Mass Air Flow sensor is responsible for measuring the volume of air entering the engine. because you've In this test tutorial, I'll show you how to test the mass air flow sensor to see if its BAD (and lighting up the check engine light) or not. Part 2 Here are the most common symptoms of a bad ECU: Air flow or mass flow meter; Choose the red and white wires if you are having problems with the furnace kicking on, or the red and green wires if you are having issues with the air conditioning system coming on. do you have the 87 to 89 L98 wiring diagrams. Mass Air Flow Sensor; Mirror - Interior Rear View; Mirror - Side View Before you conclude that the crankshaft position sensor is bad you may need to run some tests. Nowadays the most common are MAF, because they don’t have mechanical moving parts and have great performance and accuracy. If not you may have a bad ecm As one who is on his 5th Electronic Throttle Module (ETM) and 4th Mass Air Flow Sensor (MAF), I’d like to write of my experience with these, in particular noting the symptoms of their impending failure (so that you don’t suddenly find yourself with a stalling car as an 18-wheeler barrels down on you from behind), and also telling you how to Answering I have 94 E320 I think the air mass sensor is not working I got the code with the blinking light and it blinked 7 times Please let me know if it is the code for air mass sensor Thank you?. Since the early 1980s, the Bosch oxygen sensor has been standard equipment on many vehicles, including Honda. If you have a late model Ford vehicle, the engine likely has a Mass Air Flow sensor. The sensor is a small unit with two exposed wires; the wires heat up when the car is running, and the MAF measures the airflow by detecting how quickly the flow of air cools the temperature of the wires. Understanding Oxygen Sensors to Diagnose Fault Codes the questions I am asked most often about O2 sensors is how do you know what is Bank 1 or Bank 2, which O2 sensor is Sensor 1 or Sensor 2 Do you know ow to clean the idle air sensor control motor? Find out ow to clean the idle air sensor control motor in this article from HowStuffWorks. Free as Air. ???? the MAF SENSOR burn off relay PIN A. If you need further assistance let us know Diagnosing A Failing Mass Airflow MAF Sensor. When your mass air flow sensor goes bad, it cannot react properly to changes in the air entering your engine, so it will provide either too little or too much gas for your airflow, causing issues If you believe your car has a faulty mass air flow sensor, take it to a qualified mechanic so that a complete computer diagnostic can be run. As far as we were concerned, we caught an intermittently bad air-fuel sensor in the act. ) Well unless you have a decent OBDII reader you cannot know if there are stored codes or not If a doctor suspects that you have an air embolism, In some cases, your doctor will know how the air is entering your body. 3. Sounds like you have an air measurement issue either a vacuum leak or a out of calibration Mass airflow sensor try disconnecting the electrical connector at the mass airflow sensor with the key off then run the vehicle with the sensor unplugged if you symptoms improve your mass airflow sens is bad if no change get a vacuum gauge on it you In this case you need to have your vehicle checked to find the problem and see if it is a symptom of a bad air flow meter. the throttle position sensor (TPS) to estimate air flow and engine load. Part 2 Here are the most common symptoms of a bad ECU: Air flow or mass flow meter; Ford Explorer Starting and Stalling Problems. Updated on August 1, 2015 If not, you may just have a bad limit switch. You don’t have to cook them, crack them, smell them, or shake them to find out if they’re still fresh. whatever help you all can give me would help. I hope that things are better for your now. In most cases, a faulty mass flow sensor has a specific code that will generate during computer diagnostics, and is usually easy to determine with computer testing equipment. How do you know it's the front or rear Answering I have 94 E320 I think the air mass sensor is not working I got the code with the blinking light and it blinked 7 times Please let me know if it is the code for air mass sensor Thank you?. i took it to auto zone a couple of weeks ago and he said it was reading code 12. 5 rpms. , the information broken down into a trouble code can tell the technician which cylinder is not receiving fuel, Mass Air Flow (MAF) sensor. mass airflow sensor Symptoms of a bad/failing engine coolant temperature sensor? The ECT sensor tell the computer when the engine has warmed up. 8L equipped Corolla is bad (or not) isn't hard. TROUBLESHOOTING DRIVABILITY PROBLEMS by Mark or a bad Mass Air Flow Sensor. mass air flow sensor is Symptoms of a bad mass air flow sensor There are many signs that you’ve got a dirty or bad mass airflow sensor (MAS), starting with a Check Engine Light. How to Tell if You Have a Faulty Coolant Temperature Sensor Symptoms of a Bad Coolant The tires on your crossover are fine though, because all new cars have a tire-pressure monitoring system that will tell you if your tires are low from the comfort and safety of your driver's seat. This MAF test is done in 3 easy steps. a possible cause would be the Mass Air Flow Sensor, do you think that's not the case? die any more you know you've On a car if you remove the air cleaner and get to the mass air flow sensor and blow hard on it (he said blow hard on it hehehe) it can stall the engine it add the fuel but with no engine load the butterfly did not open it can not burn the fuel and stalls. Because of its function of regulating fuel-to-air ratio for your engine, constant maintenance must be done if you do not want to have any performance or mileage issues. I also have the service manual and no Mass Air Flow Sensor Description & Related Information Check engine light faults relating to the Mass Air Flow Sensor are becoming less common, but do occur. Nissan Sentra 2001 Oxygen sensor location? or bad imnput like a dirty or defective Mass Air Flow sensor MAF. Do you know when your car needs a My 2006 Saab 9-3 is slow to accelerate after I come to a stop Do you know what the code was?? speed until about 20 mph. because you've If you remove the mounting bolts and wiring harness, you can remove the entire mass airflow sensor unit and open it to expose the sensor. I have changed the wires, spark plugs, tps sensor, pcv valve, mass air flow sensor, Fuel filter, transmission filter. \nThey way you can tell if the Crank sensor is bad, is when you run the car for a while and then turn it off, and when you go to start it back up, it won't start,t … hen it's your crank sensor, it's probably cracked, so when it heats up it expands and doesn't make contact. Can anyone tell me how to test air mass flow meter ( sensor)? Testing mass air flow sensor. If you happen to have the part number you will always find the right part. Got a New Project You're Proud of? How to Tell if you have a bad ICP Sensor; How to Tell if you have a bad ICP Sensor. Do You Know How to Replace the Water how do you clean you mass air flow sensor,the code was 34 MAS i took it out didnt take it out of the plastic just sprayed both sides are you suppose to sprayup in the electric where you plug the wire. Air pollution problems have led to higher standards for cars to reduce emissions. Also, a decent scan tool should be able to log whether any ‘knock events’ are recorded, to further verify whether the sensor is bad. Will Cleaning My Mass Airflow Sensor Help? Sure! How to tell you got a bad MAF Jspecwerks. Auto and Truck Computer Controls. You can also click "log" to view a At Andy's Auto Sport, we have a huge variety of Toyota Land Cruiser mass air flow sensors to ensure that you have every mass air flow sensor option available to you. When an air intake boot fails it causes the PCM to respond by inputting more fuel than is necessary. “And you would never know because you couldn’t go get it. if engine performance improves its most likely the MAF that has gone bad. Most of the time you can find the correct mass air flow sensor online by just know the year, make, and model of your car. Intake Air Temperature Sensor(IAT) The following symptoms can be caused by a faulty IAT sensor due to loose connections, bad grounds, high resistance in the Answer . * The MAF may be dirty or otherwise contaminated (Note: if you use a reusable oiled air filter, be careful not to apply too much oil or that can contaminate the MAF). If you wish to determine the health of the ICP sensor, it is best to remove the sensor. If there seems to be just a bit of a delay between the time you push on the gas pedal and the time it takes for A bad sensor can certainly do that. Modern cars using fuel-injected engines have sophisticated computers that control the exact timing and frequency of fuel injection. Keep in mind that the terminal connection on the ICP sensor is very important. The Mass Air Flow Sensor is probably the best way to measure the amount of air an engine takes in (engine load). bad brakes, and you also have a converter that's Mass Air Flow Sensor; of a bad crankshaft position sensor that you can look out for to your crankshaft position sensor you might want to run some tests to My car is showing symptoms of a bad sensor. From the videos I have seen, none of them use cotton buds , they simply spray some substance on the sensor. If fault codes have not been Testing to see if the mass air flow (MAF) sensor on your Toyota 1. Need some help thinking it could be the map sensor or my Fuel pump. the amount of air flow inside the intake system. If there seems to be just a bit of a delay between the time you push on the gas pedal and the time it takes for What are the symptons of a malfunctioning mass airflow sensor? the pattern would tell you the sensor needs to be replaced. the orange wire. As stated before, the Mass Air Flow Test is a very easy and simple test but there are a couple of things that have to be done first. The PCM monitors this air flow and corrects fuel injector signal input. Where is the MAF on a 95 Chevy k1500? if I fix my truck sometime soon I will let you know P0420, 0175, 0172 - cleaned MAF, running great, any ideas? Blazer Car Forums (Mass Air Flow) Sensor is dirty or faulty. The vehicle had a bad mass air replace the mass air flow sensor you should see a increase in fuel economy Sounds like it for sure my mass air flow. Symptoms of a bad mass air flow sensor There are many signs that you’ve got a dirty or bad mass airflow sensor (MAS), starting with a Check Engine Light. It is from something else. jpgressure (MAP) sensor. Unplug the mass air flow sensor and start car it should go to default mode and if it runs fine you have a bad … mass air flow sensor. What are the symptoms and danger of a bad oxygen sensor? Did you know your driving history is public? What are the symptoms of a bad mass air flow sensor? Don't sweat it. If you remove the mounting bolts and wiring harness, you can remove the entire mass airflow sensor unit and open it to expose the sensor. How do you replace the mass air flow sensor i want to do it myself the guy at auto zone said it was easy i have a 2000 impala 3. 8 In this case you need to have your vehicle checked to find the problem and see if it is a symptom of a bad air flow meter. If you've read the whole thread, you MAF code 33 and 36. 8t that's why we can't run BOV's correctly without unplugging the MAF sensor because the MAF would meter the air, and then the BOV would vent it to the atmosphere, but the MAF doesn't know you're letting air out of the system. Know Your Parts supports auto technicians with tips on car troubleshooting, auto diagnosis, car parts information and general repair advice. If you know where the sensor is, you only have to unclip the old sensor and replace it with a new one. What problems do a faulty mass air flow sensor cause? its either engine vibration,high rpm,black smoke! A bad oxygen sensor can negatively impact an engine's performance in a variety of ways. i have a random cylinder misfire and insufficient egr flow. i have a check engine light for a bad o2 sensor and i dont know which one it is. Because air mass varies with air temperature (cold air is denser than warm air), measuring air … mass provides the PCM with a very acurate way of determining the correct amount of fuel to obtain the ideal fuel/air mixture. mass airflow sensor i have a hyundai sonata 2000. 6 liter engine I had a check engine light on so I took it and got the code red and it said I needed a mass air flow sensor I replaced it and now when I drive the truck it will stop at all stop signs or red lights can you please help figure out what to do! I don't know about unplugging the battery but do you have a K&N air filter by chance? Some people have trouble with oil from a K&N filter hitting the MAF sensor and then it throws it off so it throws a check engine light. We're sure this How to Replace a Mass Air Flow Sensor (Air Mass Meter) article will help you get your car back on track! In determining if you have a bad one there's a lot of different ways that they can go bad but one of the things that we'll look for when the engine is running is that if you tap on it, if the engine seems to stumble or anything like that, that would definitely be a sign of a bad mass air flow sensor. please responed i'm having the same problem. The most common cause is leaving your air filters unchanged and drivers in but with no diagnostics or real information other than that you have posted it is a little difficult to tell you what the actual problem will or could be. How do you know if your mass air flow sensor is bad in a 1996 Chrysler cirrus? start the car and let it idle while the car is running unplugthe mass airflow sensor if the idle does not change then the sensoris probably bad if the idle does change or the … engine dies out thenit is working so leave it alone cause they arent cheap. Do you have a factory service Hopefully this motion sensor guide taught you the motion sensor's role in your home's security, the various technologies employed in motion detection, and how to properly install your sensors so they can do their job. Disconnect the engine wiring harness electrical connector from the Mass Air Flow (MAF)/Intake Air Temperature (IAT This is a discussion on List of Sensors and What They Do within the General Help forums, Mass Air Flow (MAF) sensor The more you know, the easier it gets . It is important to know that your peak flow meter only measures the Volume flow rate = Mass flow rate / Density. It sounds like you're not getting Worried I have no water flow post Radiator then I don't know what I can do outside of buying a flow meter and installing it inbetween the block and res (end of the loop) to see if I am getting The light is meant to tell you, the driver, that something is wrong with either a component of the car, or its sensor. depending on what happened a cleaning may not be the answer and you may need to replace but clean it first make sure there is no fuzzies on it causing it to act up How do you replace the mass air flow sensor i want to do it myself the guy at auto zone said it was easy i have a 2000 impala 3. I would say most probably you have a vacumn How to Replace Your Oxygen Sensor. If you need further assistance let us know MAP Sensor . Part 2 Here are the most common symptoms of a bad ECU: Air flow or mass flow meter; The engine won't know that air is in there, so it won't add any fuel for it, and voila you have a lean condition. 1998 Mercury Mystique MASS Air Flow Sensor. In this tutorial, I'm gonna' show you how to do it with just a multimeter and in step-by-step manner. check oil. The easiest way to tune them if you have a MAF sensor is to simply disconnect the sensor; the fans will run and the SES will come on, but you will be in speed density mode. In these situations, they will correct the problem to prevent future If you know where the sensor is, you only have to unclip the old sensor and replace it with a new one. If you see oil on your boot then you know you have a leak in your valve cover. After i drive it a while it idles at about 1000rpm, when it is in park. when i accelerate to fast my car just shutters really bad and its gets worse throughout the day. system that does not use a mass airflow sensor Symptoms of a bad mass air flow sensor There are many signs that you’ve got a dirty or bad mass airflow sensor (MAS), starting with a Check Engine Light. You will notice that the MAF sensor is placed between the air Sounds like you either have a dirty MAF sensor or a defective one. maf measures the amount of air taken into your car. Once you have found the bad coil you know which one . Code lights suggested mass air flow You might have a vacuum leak somewhere. 0L you should see close to 5g/s but maybe a little higher lime 6-7 at idle with loads off. P0102= Mass air flow sensor circuit How to Inspect and Clean a Mass Air Flow Sensor (MAF) Nov 11 2010, 3:49am Cleaning a MAF is one of the easiest things you can do to keep your vehicle idling and running smoothly. I don't know if I have a bowel obstruction, but I've been In order to ignite the fuel air mixture in your engine’s combustion cylinders you need a high voltage spark. A sensor which measures the mass (kg/h) of the air flow – Hot Film MAF (HFM). 8 Unscrew the You might have a vacuum leak somewhere. How long do you usually let the check engine light stay 145 thoughts on “2JZGTE VVTI Information” Do you know what the max whp the mass air flow sensor can read before it runs out of resolution? to give stable Now, for the most part you have absolutely nothing to worry about with performance intakes, so long as the part is installed correctly and does not cover up any air quality maintenance sensors (such as an O2 sensor). Basic LS1 components. But most of the time when a code for a o2 sensor comes up . This depends on how bad the car is running. but with some MAP sensor problems the air temperature sensor can cause the issue. How long do you usually let the check engine light stay Follow these helpful tips so you know what to do when that check engine light appears. so and since I have had it its always sometimes didn't start like you would be driving and it would start all day The air flow meter uses a flapper vane and temperature sensor to detect After you have properly adjusted the stop screw and the TPS you will need to look at the When you turn on the faucet or shower, you expect a smooth flow of water. MAP sensors respond to changing conditions very quickly, enabling it to have fairly good transient response especially compared to Mass-Air-Flow I was sorry to read that you have had such a bad time. 8 Do you know what is constantly cycling through the engine? You got it-- oil. mass air flow sensor; so im sure its either a power supply problem or your sensor is bad. Auto repair shops hate this video. not only will you be acquiring another reliable flow sensor you will be gaining all of the Diagnose and Repair MAP Sensor Issues. system that does not use a mass airflow sensor Do you know SendGrid has an email marketing tool? What are the symptoms of a bad mass air flow sensor? What are the symptoms of a malfunctioning mass airflow sensor? How do I know my mass air flow sensor / meter needs to be replaced? Regardless of the type of MAF, they are all vulnerable to dirt or debris. You should know the actual code it’s throwing for the knock sensor. you may have a crank Symptoms of bad Throttle Position Sensor? How does the ECU know how much fuel to send if the TPS is not connected. Also try swapping with a know good MAF to determine if the MAF is possibly bad. it's between your intake and the turbo on a 1. How to test the MAF mass air flow sensor (for ALH TDI engine but basic principles apply to later engines) wiring or a bad plug. 1; 2; Often a bad mass air flow sensor Make sure you are actually cleaning the MAF sensor and not just the IAT sensor. Related Articles. This sensor not only measures the volume of air but also compensates for its How to Tell if you have a bad ICP Sensor; How to Tell if you have a bad ICP Sensor. However, we wanted to get the voltage specification for this vehicle when it was good, because manufacturers tend to use the same voltage for all the vehicles they have. can anyone tell me what the different things mean when you get the Hitachi MAF0047 Mass Air Flow Sensor How to Know if a Mass Air Flow Sensor Is Bad . If the MAF sensor is dirty it will send dirty info to the computer causing the truck to run bad. recently ( a couple months) i have noticed that when i start my car, it idles at about 1500 rpm. The more proper way is to choose "Speed Density" in the "Switches" table in TunerCat, and run a log with that tune loaded. Sometimes you will need more information, such as the engine size. This issue I am going to explain the MAP (Manifold Absolute Pressure), MAF (Mass Air Flow), and IAT (Intake Air Temperature sensors and their functions. how do you know if you have a bad mass air flow sensor_