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Changed MAF about 2 weeks ago, light still on

the check engine light came on a little bit ago and we got it tested and it was the mass air flow sensor, we recently about 2 weeks ago changed it but the engine light remains on and i know its supposed to take a minute to go out but its been longer now, also every time i get gas (it did this before i changed the MAF as well and was a result of needing to change it) and i turn the car back on the entire car shudders and goes quiet like its stalling out or something, it usually takes a few seconds to get back to normal or else I have to just turn the car off and turn it back on again and its fine, but it is still doing this after its been 2 weeks and the gas gauge now seems to be slowly fluctuating like earlier it was at the last tick mark and then after about 10 minutes it was suddenly at the middle but then it evened out again but still

When you change a MAF sensor, you need to disconnect the battery for about 10 minutes so the computer forgets the learned parameters and resets to the factory parameters. Then it goes into learn mode and may take a little while before it learns all the parameters of the new MAF sensor.

Both of these statements make me think that you have at least one poor connection at one of the battery cables. Either at the battery , or at the other end of the cable. Be sure you take the terminals off and clean the terminals and battery posts. Just brushing off the outside is not enough.


You may have more than one problem. The poor engine performance after filling up w/gas makes me think you have a problem in the evap system. When you fill up w/gas the fumes in the gas tank are supposed to be pushed into the evap canister. Then when you start the engine after a fill up the evap canister is supposed to hold onto those fumes until you get up to a certain speed or engine load, at which point the evap canister (the purge valve) is supposed to open up and meter those stored fumes into the engine to be burned. If the fumes are allowed directly into the engine when the car is first started (after a fill-up) or at idle it will run too rich to compensate for, and cause this sort of symptom. The fuel gauge symptom could be related to an evap problem too. Generally that would throw a code for fuel tank evap pressure or something like that.

Evap problems can mask themselves as MAF problems too, so it’s possible the MAF wasn’t ever a problem. Unlikely, but possible.

As others have stated… After you changed the MAF you needed to clear your code… Without a tool you simply disconnect the battery for a few minutes. Then test the vehicle. IF you get another MAF code with the new sensor and after batt disconnect… Your air filter is clogged. If the new MAF doesnt detect proper airflow it will register as a bad MAF.

I would remove or replace your air filter and test…straight away.

Anytime you get a check engine light you need to reset the ecu…either with a tool…or by batt disconnect. A tool will save you much frustration and help you in many many other diagnostic ways.

Personally, I’m kind of doubting the accuracy of the diagnosis


I would respectfully disagree with mandating code clearing for the following reasons. 1: when contitions are met the computer will turn the check engine light automatically. Sometimes the ECU does not instantly check the repaired system and light May stay on for the first few times of driving. 2: If you clear the codes and do not remedy the problem yourself, you may taking your car to a mechanic, and you may have (probably have) made his job much more difficult if all codes have been cleared. Almost always the ECM does a very good job at clearing itself and maintaining memory of past behavior.

Also consider that an MAF check engine code can be due to a vacuum leak; i.e. unrelated to the MAF sensor. You could try the experiment. As a test, purposely introduce a vacuum leak on an OBD II car with no codes. You’ll likely immediately get a check engine light and a code for the MAF sensor or for the o2 sensor.

Many times when you change a MAF…you neglect the air filters integrity… A clogged air filter can manifest as too little or erroneous airflow levels at the MAF when compared to throttle position and RPM. Then it assumes the MAF is faulty.

Sometimes its the filter… Seriously…

I have changed my mass air flow sensor twice with OEM parts, reset the code multiple times, put a new K&N air filter in and the light still comes with in 3 or so miles. I have a 2017 Titan XD with the Cummins. I did find a skinned wire that looks like a rodent got it but I soldered it back together so it is solid.

Please start your own thread.
The problems with the original posters gas powered Toyota are going to be totally different than you Diesel powered Nissan.

Also post the Diagnostic Trouble Codes we want the numbers Pxxxx