BCook839

My Bank 2 upstream O2 sensor went out. Who here would just replace the one sensor, or replace both of the upstream sensors on the car? I ask because I didnt know whether or not to be concerned with how the new sensor's readings would compare with the old one on the other bank. Will it effect the feul trim levels from bank to bank and cause drivebility problems?

The sensors are only 53 bucks a peice at my local parts store. I'm tempted to replace both.

Thanks

RamAir95TA

As a maintenance procedure, it definitely wouldn't hurt to replace both. Make sure you use AC Delco sensors though...lots of people have reported issues with other brands.

Guest47904

AC and GM's are made by Standard. If your auto parts store doesn't have either of the 3, move on till you find them.

Injuneer

Did you determine that the O2 sensor "went out" from a code scan? If so, give us the exact code. Some O2 sensor codes are caused by problems other than the O2 sensors themselves.

BCook839

I cant remember the code's exact number but it was a P015X. It's title was: Bank 2 Sensor 1 Heater circuit malfunction. I checked the pid levels coming from the sensor in the data stream fuction of my buddies MAC Tools scan tool. The wave, though not too detailed on the little bitty screen, was virtually identical to the wave coming from the other O2 sensor on the Bank 1. And feul trim levels were good. So im thinking that it really is just the heater circuit, and the sensor is reading fine once it does finally get up to temp.

I checked with my local IWI parts store, and they carry the AC Delco sensors for 90 bucks a peice. I think i might just go with the one sensor for now.

Thanks

Injuneer

Have you checked the wiring to insure you have 12V (brown wire) and a ground (black wire) at the harness connector?

StangCrusher350

bro, you can get the acdelcos from their site for 69.99 a piece.

BCook839

Injuneer, I have not had a chance to crawl under the car yet to do so but I sure will before I go buy the sensor.

I figure it is worth saying, this is why i jumped on it deffinatly being the O2 sensor being faulty; The header colector that this O2 sensor is connected to, was leaking terribly and i drove the car a couple times with this problem before i was able to fix it with a better type of clamp. I think this is why the sensor is screwed up, as I have heard other people complain that O2's can be fouled out by running open headers or a bad exhaust leak.


Thanks for the tip StangCrusher350, I will check out their site.

Injuneer

The O2 sensors are not "fouled out" by being in an open collector, or being downstream from an exhaust leak. Those problems cause the sensor to read inaccurately, because of the air mixed into the exhaust gasses. The sensor isn't "fouled", its "fooled". No physical damage is done, and eliminating the source of outside air will return the sensor readings to the correct values.

Additionally, excess cool air being added to the exhaust can slow down the sensor heat up. The heater circuit check is based on the PCM measuring the time required from a cold start for the sensor to start being active - an indication that it has reached the minimum temperature required for it to operate. The PCM infers that if the sensor is not heating up fast enough, there is something wrong with the heater.