Check engine lightp0170 fuel trim bank one check engine code the light stays on problem comes and goes runs rough feels like its going to stall untill i press hard on the gas and runs fine again have changed plugs wires filter
Cars & Trucks - Subaru - Forester - 2001 Subaru Forester
Answers & Comments
I'm guessing your mixture is too lean and it's possibly running a bit rough and there isn't enough fuel getting to the engine. A rich mixture is too much fuel, but that error is usually related to O2 sensors. It might be the O2, but 'trim malfunction,' you're looking at a vacuum leak. Check the oil separator valve then the throttle body gasket and then the intakes. Most likely a vacuum leak and the throttle body, oil separator and intake are the most likely. Run your hand around the bottom of the throttle body and oil separator, if it's greasy/oily there, there's a leak.
If there is no leak, test the MAF sensors...they might need cleaning, and in a worst case scenario, might need replacing.