'95 Pathfinder VG30E: Check engine light: Code 33

[chris8042002]

Newbie to this forum, but have been lurking for a while.

Here goes: Almost every morning when I start my Pathfinder, I get a check engine light almost immediately, and some rough idling......take off down the road, and experience surging, hesitation, stumbling, near stalling at stop lights......after 5 minutes or so, the light goes out, the rig runs perfectly, like a top, and will do so for the rest of the day.

Pulled codes today, got a 33: Exhaust Gas Sensor

My confusion: After doing some research on this forum and others, it seems like the O2 sensor doesn't come into play when the vehicle is first started and cold. Should I just trust the code reading and replace the O2 sensor, or try something else (cheaper!) first? Could someone please explain the function of the O2 sensor in a cold engine?

Thanks in advance, and I'll be sure to provide updates on this issue when I tackle it.

 

Chris

[Simon]

Mine did that when my O2 sensor was bad......though, my CEL stayed on constantly.

[GhostPath]

Replace the O2 sensors. IIRC, that's a three or four wire type, so it's heated. That means that the computer starts looking at it after 30-90 seconds.

 

If the heater isn't working because of age killing it, you will get that code.