on my way back from champaign last night my CEL came on car was running fine and all the guages checked out ok so i kept going. my datalogger of course ran out of batteries a few hours earlier and i lost the program so when i got back home i reloaded it and found i was throwing my O2 code. i was looking in the haynes and it said it could be O2 sensor, fuel pressure, injectors, or one other thing can't remember right now. the car still runs strong so i am assuming (i know what happens when you assume) it is just my O2 sensor. so the question is should i buy a new/used sensor or wire in a new bosche sensor? has anyone tried the bosche sensor? i have heard that the 3S doesn't respond well to the bosche. and the second question is does anyone in the area have a parts car with an O2 sensor that they could let go of for a reasoable price?

Hook your logger back up and view your O2 sensor voltages. I believe the voltage should be fluctuating at idle when the sensor is warmed up (just like the blinky light O2 gauge).

If the logger shows the voltage is never changing that should be the dead O2 sensor not changing its readings I believe.

As to the Bosch, hearing a bunch of stories about them from Spooled91 convinced me to stay OEM.

I'll scrounge around the shop to see if we have any spares on hand but it looks like Spy's pretty much got you covered there.

If you go the new route, we should have factory Mitsu ones listed soon.

I used this sensor until I got a wideband. Its nice because it is resistant to leaded gas, in case you ever use leaded at the strip.

http://www.machv.com/denoxsen.html

I used a Bosch on my old GST daily driver. It didn't seem to respond differently with it versus the OEM but I'd probably put an OEM one (or the Denso Nate listed for leaded gas)on the TSi just as a precaution.