Diagnosing lean condition
Hey Scotty and the community!!
Hope y'all are having a nice day
2003 Corolla, 1.8L, 135k miles, manual, no codes
At idle, my MAF reads 1.4 to 1.5 g/s
Short Term Fuel Trim is between 3% and 7%
Long Term Fuel Trim is 8.6% (after driving)
O2 sensor shows values below 0.45V more often
Can this lean condition be simply due to the MAF sensor?
I've cleaned it twice, replaced all the intake gaskets, got new OEM air filter from the dealer.
Car sat for prolonged periods of time before I bought it, fuel filter may be clogged
Cheers, sorry for the long write up. Scotty has said these can be made to run perfect, and I do want to keep the car as long as possible!
Typically a lean condition means you need MORE fuel, not less. It is when a car is running rich that MPG goes down because the injectors are dumping too much fuel.
I would start by running a bottle of fuel injector cleaner through it to see if it helps. Also check the fuel filter to see if it is clogged.
Those short and long term trims wouldn’t indicate a lean condition.
What kind of symptoms are you experiencing?
Have you checked for vacuum leaks?
If your not getting any codes it sounds like it’s running as it’s designed to. All electronics like the ecm have built in parameters or limits of sensor readings and specs and will trigger a code when something is seen above and beyond what it should be. I would leave it alone