I keep getting an PO141 on my 03 Monte SS with 81K on the clock with stock exhaust. I have done some searches on this site, but many are complaining about the code if they do some cat back work on the exhaust. I know the PO141 is for bank 1 sensor 2 and I have seen a few people discuss it could be a bad ground.

I have two questions:
1. Any common fixes or problems (like a bad ground or do I need a new sensor)
2. Say it is a bad ground and I fix it, will the Check Engine light go away or will I have to go to Autozone and get teh code cleared and see if it comes back on??

Thanks,

 

I don't have the Haynes manual with me at the moment, but the code means the cat is under performing or the sensor is bad.

You can have an Auto Zone or repair shop clear the code, however it may go away on its own.

I don't have a cat on my car, and I get a CEL that throws a no O2 sensor code. Some days it is there others it picks up the O2 Emulator and all is fine.

 

Odds are if the wires look good you have one of two things going on:
1. - Bad O2 Sensor
2. - Bad CAT

Bank 1, Sensor 2 on these cars is the "down stream" O2 sensor, behind the CAT. It's used to "check" the health of the CAT (nothing more). I believe this is the code that my wife's '05 Impala threw when we first bought it. I opted for replace the O2 before the cat (cheaper option AND it's recommended you periodically change the O2 sensors, as they age, they may not read accurately).

I replaced the rear O2 sensor and the code cleared itself. I know some people have complained about problems with BOSCH O2 sensors, I have had luck so far with them (on mid 90's 3100's and the '05 Impala, but I used a Delphi on the upstream O2 for my '04 Monte). A guy I know how is a GM Mechanic recommends AC Delco and Delphi branded O2 sensors for best success.
Be prepared for removal of the old one to be a pain, as the space to work it is TIGHT. Took me about an HOUR to get the one out of the Impala. I had to cut the wire and use a true deep well socket for removal. Installing the new one took like 10 minutes.

 

There is a lot of bad information in this thread. No offense to you who posted, I know sometimes you read it's one problem and don't look it up and give all the information you know for that problem but,

The P0141 code is for the FRONT BANK O2 sensor. The one on your rear exhaust manifold. There is a problem with the heated circuit.

P0420 is the code for the REAR BANK 02 sensor. The one on your downpipe after the cat.

This code means that the heated circuit in the oxygen sensor on bank 1 decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The PCM tracks how long it takes for the oxygen sensor to begin switching. It the PCM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0141.

You either have a short in the wiring, or an internal short on the sensor. I would replace this whole sensor.

From the dealership it's probably a $100 - $140 part (depending on their mark-up in your area). I bought mine off of Amazon last week (funny I just changed it) and it was only $43.

Amazon.com: ACDelco AFS109 Oxygen Sensor: Automotive

 

Doh! Followed by a good ol' face palm! Guilty as charged.

Thanks for catching that Chibi!

 

All in a days work

 

Listen to Mike, he's smart, and correct.

 

What's wrong with Bosch sensors, will be what i will be buying this weekend for mine. Both sensors, just in case.

 

I like to replace with the stock sensors, I have read numerous things about other types of sensors not giving the correct readings. Same with spark plugs and wires. So I went with the ACDelco, for the price I found it on Amazon there was no question about it.

 

I'm going Bosch because they won't cost me anything.