[QUOTE
Anyone out there have a Jetta or familiar with one? My first guess is O2 sensor. How do I check it? Should the voltage be about .45 at idle warmed up?
TIA[/QUOTE]
Had a 1997 once.
I would suspect a faulty O2 sensor to give you a CEL & set a code.
If you want to check the sensor, warm up the engine, backprobe the signal side of the O2 connector & you should read an oscillating voltage of @ 0.1 to 0.9 volt.
Remember, a 4-wire sensor has 2 ground wires, 1 - 12 volt ( heater ) wire & 1 signal wire.
