I had a broken exhaust front pipe on my 2003 TT 225, so I replaced it with a pipe from RockAuto. Then I immediately started getting a code P0130 (front O2 sensor). I could have possibly bent the sensor wire too much during my work, so I got a replacement, but same error. No other related codes. I borrowed a friend's scanner (not Volkswagen specific) and saw that O2 sensor EQ_RAT and O2S readings seem OK except when when the engine is at some moderate RPM and i snap the throttle shut. Then it's pegged at about 1.999 and 3.2222, until it hits idle. That seems to be when the fuel system status goes from CloseLoop to Fault, and logs the DTC. But my current understanding is that those readings are expected in that situation as the fuel is cut off during that period.
One thing I noticed of concern is that the sensor hole on the new pipe seems to be thicker than on the original pipe. I thought maybe that would cause a problem, but the sensor seems pretty long and should still reach into the airflow. I put the original O2 sensor back in and it looks alive (I get similar readings), so I don't expect the sensors are broken at this point.
Anyone have any insights? I'm not sure where to look. I didn't replace the turbo to exhaust gasket with a new one. That couldn't be it, could it? Emissions is due next week, of all the luck.
Thanks
Rock
One thing I noticed of concern is that the sensor hole on the new pipe seems to be thicker than on the original pipe. I thought maybe that would cause a problem, but the sensor seems pretty long and should still reach into the airflow. I put the original O2 sensor back in and it looks alive (I get similar readings), so I don't expect the sensors are broken at this point.
Anyone have any insights? I'm not sure where to look. I didn't replace the turbo to exhaust gasket with a new one. That couldn't be it, could it? Emissions is due next week, of all the luck.
Thanks
Rock
