Originally Posted by
pdqford
Your HO2S may be dying, or the problem could be in wiring to the HO2S. (Or you may have a fuel issue (pressure, injector, etc). To save some $$, you could try swapping the left and right HO2S and if you then get a P1131, the HO2S is the culprit.
Thank you. What exactly are you referring to when you say HO2S? I recently replaced the #4 coil pack, and the PCV valve position sensor switch(? I think that's what it was. It was a little black box above the engine on the driver's side, it had two vacuum lines running into it, and an electrical plug.)
Eric