Hello me again so i crunk my jetta up yesterday and i plugged my scan tool up to read the live data while the car was running. And i look at my fuel trims and they are at 25% off the throttle. but when i give it gas the fuel trims act like they wanna go back to 0% i bought the car with 260 000 miles and another thing it got that stupid blue intake filter thing on it were the air filter box go could that be causing my lean condition??? Do i need to go back stock and i should be fine?? Need help plz thanks she runs rough as hell.
If you are getting +25% fuel trims, you have:
1. A rich condition, not a lean condition. In a lean condition, less fuel is sprayed into the motor by the injectors. In a rich condition, the injectors are dumping too much fuel into the motor.
2. Likely bigger problems than an intake filter.
I would do two things first. Clean the MAF sensor and throttle body. Here is a video on how to do it:
After that, check to see what your fuel trims look like. I would guess you will still have too much air, so you will need to check for vacuum leaks. Check all the rubber hoses, plastic pieces, etc. for any holes or cracks. And here is how you can do that:
If it is STILL off by a lot, the motor is probably just worn out at that mileage. I'm surprised it made it that far to be honest. Good luck with the repairs!
@mod_man I thought if the fuel trim was positive that the air/fuel mixture is lean and the computer engine compensates by adding more fuel. If fuel trim was negative the air/fuel mixture is rich and the computer subtracts fuel.
@DayWalker Yeah I got dyslexic on this one. Sorry. No sleep in 4 days finally got me. {black}:scared: My advice would remain the same though. It's like the bottom half I got right....it has too much air. But my brain was checked out on the first part. Ugh.
misdiagnosed, but the prescription was still correct, so nobody can accuse you of malpractice 😉
@mountainmanjoe You can be my attorney any day. {black}:laughingoutloud:
But i got good compression in the engine and like i told you guys when i bought the car it had this fancy cold air intake on it and it's not stock Scotty kilmer said go back stock and you should be fine the fuel trims should go back to 0% or closer to it anyway 😆
Well if you want to go back to stock, go back to stock and see what happens. {black}:idontknow: