02 Sensor Problem?

[One1999Chev]

So I took my 1999 Chevy Classic home today and it was running really rough, I backed out of the shop and it completely died on me. It fires right up fine but idles like crap.

I have a check engine light on and had it diagnosed and I know it's O2 sensor codes. Is this why my truck is running rough? When I first bought it I drove it for 4 hours and it did not show these symptoms. It has been sitting in the shop for a few months though.

Where can I order new O2 Sensors for cheap? One shop I took it to quoted me $300 to change 3 O2 sensors. Upstream and downstream sensors.

Any feedback appreciated, I would like to have the truck running better than it is now.

 

[east302]

What were the codes (numbers)?

Check RockAuto for oxygen sensor part numbers. I bought ACDelco ones for my 98, think they were $30-something each.


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[olduglyforeman]

UPstream o2 sets your fuel trim iirc downstream is cat performance.
NOrmally i would replace the 2 upstreams and retest. Even amazon carries o2 sensors.

 

[Tom P]

Amazon has the best prices on O2 sensors that I've found. Delco, Denso, and Bosch are probably the only ones I'd buy and they are reasonably priced. In some cases 40-50% less than the local stores. Free 2-day shipping is nice too. For 8 bucks you can buy the O2 sensor socket which would make them a breeze to change. Make sure you get some anti-seize for the threads on the new sensors you install. start and run the truck for 2 minutes or so before you do the job as well. The warm (but hopefully not burning hot) exhaust pipes will allow the sensor to break loose much easier. Quality penetrating oil is a must have. Also, don't get anything on the sensor end itself. Oily fingers, the anti-seize, if any of that gets on the probe it will drastically shorten the life of the sensor, if not ruin it immediately.

I'll be doing the job myself here sooner rather than later. 175k on the truck now.