So while driving to work last night in my 97 monte and the SES light came on. Got home this morning and threw my obd bluetooth thing on and pulled the code, P0141. What im getting from it is theres a problem with an O2 sensor somewhere? I cleared the code and the light went out, i have a trip to school today, so i'll see if it comes back. If it does, what do i need to do?

 

You need to check the wiring going to your o2 sensor on the manifold, and replace the sensor.

 

I believe the O2 sensor that code is referring to is on the rear exhaust manifold. On the 3100 and 3400, the peak down between the coil packs and the firewall, you will see a thing with a cord sticking up from the exhaust mani. If you can't see it (which on the 3100 in my old '94 Grand Am it can be), remove the 2 bolts and 2 nuts holding the coil/icm assembly down, then lift it all up and set it to the side (no need to disconnect plug wires). You should see the O2 at that point.

Check the sensor wiring, make sure it's not damaged, but odds are it's a bad O2 sensor. Since they are heated and the heat element breaks down of time, it's typically recommended to replace them every 70,000-100,000 miles.

For removing, I usually end up having to cut the wire as close to the sensor as I can and put a deep well socket on it (as my O2 socket won't hold as tight as needed for a removal but works great for re-installation). During removal, I also usually have to get about 4-6in of extensions, have the ratchet clear of the engine and slide a pipe or use a breaker bar on the thing to get it out (due to the heat and what not, those things can have a heck of a grip for removing, but re-install has always been a piece of cake).

BTW - Get a ACDelco or a Delphi O2 for best results with your PCM.

Hope that helps (perhaps more then you needed/wanted lol)

 

Thats helpful, i really am not in the mood for more car problems. Have to see if it the light comes back today, probably will. I assume i can get the sensor from any auto parts store? And it wont do any harm running the car til i get it replaced will it?

 

Gas mileage will probably be worse, and you could technically be running rich.

That o2 sensor and MAF tells the PCM how to adjust fuel.

 

Alright, i'll keep that in mind, the light hasn't come back on yet after a 60 mile drive to school.

 

bump, ses light is back with the same code. Is the o2 sensor something I can pickup at a parts store and change myself?

 

Yes, but don't get a Bosch. Stick with ACDelco or a Delphi

 

The P0141 refers to the heater circuit of the O2 sensor. The PCM runs its test of the circuit during startup when the engine temp is below 115° and it must fail the test twice to set the CEL. Before replacing the O2 sensor I would check the heater wiring and the fuse to verify the problem is the sensor and not the circuit.

 

I would hope he checked the wiring already, I asked him to do that earlier