Re: Another possibility...
Posted: Dec Mon 24, 2007 11:04 am
Bad 02's may not trip the CEL, but there would be errors stored in the ECU. Only a VAG-COM scan will reveal them. If you don't have access to the software, an OBDII generic scanner may help. Joe usually offers to help out...James wrote:When my 96 Golf GL with the 2.0 started acting up, it would not run well between 2200 and 3000 RPMs. It would idle great. If I stepped on it over 3500 it would take off. But trying to do 25mph down Durston was not great. It would cough and sputter. As it turned out, both of the oxygen sensors were non responsive. What baffled me is that they would not trip the check engine light unless I tried to drive out to Belgrade and back. It was not easy to diagnose so I had to take it in so that the mechanic could monitor the responses while the car was running. Expensive sensors, but now it runs like a champ.

I know Ramrod had the same type of issue with his S4, except his problem was in the high RPM range. Different motor than what you have, but same concept. If you are lucky it's the cheaper of the two sensors.
Being that you were 4x4'ing on Hyalite it's possible snow or ice pulled the wires - maybe take a look underneath where the post cat O2 sensor plugs in and see what's going on.
A Sunday afternoon GTG would solve the problem!