check engine light on, replaced maf sensor as per obd2 light turned off with obd2, 10 miles later light back on
You might have a vacuum leak somewhere. When un-metered air is getting in to intake, the OBDII uses that along with MAF, Manifold Absolute pressure sensor to correlate how much air flow should be coming in @ certain rpm. You don't say what code, but I bet it is P0100, P0101, or P0102. That does indicate a Possibly bad MAF, but could be an electrical connector problem with the MAF not the unit it's self, but that or a vacuum leak. Look for and vacuum hoses that have come off, a 2012 is too soon to have them just worn out. There is an TSB (Technical Service Bulletin) for the 2012 Nissan Altima, Bulletin No. NTB12-051d which is that if replacing the MAF and light re-appears you may have to re-program the ECU. See http://engine-codes.com/p0101_nissan.html
What trouble code(s) do you have? Please post them so we can help. -Jim
Very helpful, that was the right answer. Thank you.
That was the correct answer. Thank you.
my check engine light has been on for almost 3 years and the code reads for the Mass air flow sensor. but my car still drives. should i replace the MAF. i purchased one the other day but havent put it in yet
I got a bad maf sensor code. replaced sensor! saw tech service bulletin , called to see how much to reprogram computer which is the factorys fault that they sell the car with a glitch. they said at the dealer as the private garages said only the dealer can re program the computer since the equipment costs $100,000. I asked the dealer how much?they said first they replace the MAF sensor which I just bought. then they reprogram the defect in my computer they sold me when I bought the car new! seems it would be around $200.00. so I bought a reader for $20.00 and every time the light comes on I shut it off. I got tired of doing that so I have black duct tape which I cut out a small piece and block out the light. and since Nissan is at fault I will remember this and buy a Toyota next car but first I will remove the tape and use my OBD 2 and turn out the light before selling! you know the old saying "let the buyer beware"
How do you pass the smog tests if you have your light on but covered with tape?
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