O2 sensor causing check engine light to be on

thomasusmc · 10-20-2006

I have a 94 3.8L with a CAI & true dual CAT-back Flowmaster exhaust. My check engine light just came on a few days ago. Found out that it was an O2 sensor running lean from the guy at autozone using the OBDII code reader. He says he can't tell me which one of the FOUR O2 sensors it is. How can I find which one it is WITHOUT going to a shop.

OEM O2 sensors run $65 a piece, so I don't really want to replace all 4. Buying one and replacing to each and then clearing the code and re-reading it is possible, but I don't really want to spend that much time troubleshooting it.

Can anyone give suggestions??

89GTVert · 10-20-2006

you could pull them out and look at them, one of them might look blatantly discolored or different. that would be a good indicator

GT-EATER · 10-20-2006

Whats the exact code that would at least narrow it down to right side or left side .

thomasusmc · 10-21-2006

I found the meaning of the code, P1131, but I still don't know which one it means.

P1131 - Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1

thomasusmc · 10-21-2006

I also found I'm pulling this code;
P1443 - Evaporative Emission Control System - Vacuum System - Purge Control Solenoid or Purge Control Valve fault

What does this mean?