View Full Version : Running too rich. Is my O2 sensor bad? I have a Vag-com

02-02-2008, 08:01 AM
I can really smell the gas at start-up. No CEL or fault codes. Spark plugs are very dark. Fuel trims are 0.8% and -10.9%.

How do I tell if it's the oxygen sensor or MAFS or something else?

02-02-2008, 02:50 PM
with those fuel trims you more than likely have a boost leak after the turbo. Get pressure tested and find that hole

02-03-2008, 01:31 PM
u should get a cel if its the o2 sensor, scan the car and youll get a code

02-03-2008, 08:56 PM
I took the turbo outlet/intake manifold hoses apart and couldn't find anything. I put everything back real snug and will check the fuel trim in a few days. If it hasn't changed, I guest I'll have to make a pressure tester.