Does anyone know if Code 21 can be caused by a completely unhooked DS O2 sensor (as in wires cut)? I have replaced the upstream O2 and am still getting Code 21 after resetting the PCM. I havent traced the wires yet, mainly because its going to be a pain in the butt and I'm trying to put it off...
KYKillerKlown
09-18-2007, 03:37 AM
Code 21 is more than likely caused by the rear o2 sensor. When there is a problem with the front o2 sensor it usually causes the code that shows it running lean.
rice_eater
09-19-2007, 01:24 AM
I just spent $65 on an O2 sensor I didnt need... crap. Well, at least I don't have to trace the upstream wiring now, LOL.
Thanks for your help.
KYKillerKlown
09-19-2007, 04:12 AM
I have the same code showing right now. I think whenever I wrecked a couple weeks back and went airborn and came down in a ditch the wires to the rear sensor got ripped out. Or maybe they got ripped out when the wrecker had to winch the car out of the ditch over a concrete culvert. These cars are a little tougher than they look, LOL.
