MAF sensor PROBLEM - Toyota Nation Forum : Toyota Car and Truck Forums

corolla roy · 06-05-2011, 05:03 PM

while driving my check engine light came on. P0420 came up. Cleaned maf sensor and changed spark plugs. Also air filter. I read up and a person said he cleaned his temp sensor and it fixed his car. WHAT Temp sensor could he be talking about? Also,problems were
1. Gas mileage went down
2. car would very slowly accelerate and would not shift.

HELP PLEASE

teppista881 · 06-05-2011, 08:50 PM

Quote:

Originally Posted by corolla roy

while driving my check engine light came on. P0420 came up. Cleaned maf sensor and changed spark plugs. Also air filter. I read up and a person said he cleaned his temp sensor and it fixed his car. WHAT Temp sensor could he be talking about? Also,problems were
1. Gas mileage went down
2. car would very slowly accelerate and would not shift.

HELP PLEASE

He probably meant the coolant temperature sensor. P0420 is notoriously difficult to diagnose.

Also be sure to disconnect your battery when you're working on this stuff, and then give the car time to reset itself once you start it back up. Drive around the neighborhood slowly, etc.

corolla roy · 06-14-2011, 08:04 AM

sorry hadnt posted anything. but i cleaned my maf sensor with the spray and reset the battery. got power back and gas mileage increased. no engine light for a week. on my way to work this morning the darn light came on.Could it be the maf sensor since i did clean it and went away for a week?

fishexpo101 · 06-14-2011, 11:52 AM

Probably had more to do with resetting the CEL than cleaning the MAF sensor. It can take a few hundred miles or several days of engine cycling to "relearn" engine parameters and set the I/M parameters.

Possible that the MAF is bad, only way to test it would be to swap it out and see if the CEL stays off. If the P0420 comes back, then you have to do some more diagnostic work.