I'm working on a friends 2001 Jetta with the 2.0 non turbo engine. Recently one of the lights on the dash came on. OBD pulled the following codes for me:
P0172- System too rich (bank 1) P1128 - Upstream O2 Sesor Swapped
About the same time, the gas guage started to work erratic. It reads about 2 lines above where it should be (so when Im at 1/2 a tank, it says I have a little under 3/4). Gas mileage doesn't seem to be affected. I'm thinking this could be the MAF or just the upper O2, or maybe the MAF needs to be cleaned then consider replacing the O2 if needed. I've cleaned my notchbacks MAF before, just wondering about these little imports. VW place wanted $85 just to check it out for her. Just wondering if anyone has any suggestions on where to go from here to try to get this fixed. Working on cars like these make you glad you own a Mustang sometimes :) Thanks
Chad
69 Mach1, 93 Notch, 00 Wrangler