Location of bank 1 sensor 2 sensor 2001 buick century

Hey all! I am trying to save a few bucks on my 2001 century by replacing the bank 1 sensor 2 o2 sensor. I am getting the p0141 code so I know it is the rear sensor. One of my friends has indicated that I need to take this to a dealer as the rear sensor can only be accessed through the inside of the vehicle by removing seats and pulling caret. I do not think this is a correct statement. I was under the impression that the sensor would be accessible after the catalytic converter via the under carriage. Will someone please advise? The catalytic converter was replaced under warranty at just under 80k. My vehicle is currently at 152k. Thank you in advance!

There’s only one O2 sensor after the cat. Your vehicle didn’t come with dual exhaust so there’s only one.

Look under the vehicle after the cat and you should see the O2 sensor. You’re going to need an O2 sensor socket to replace the sensor.


I think on this car, you do have to go inside the vehicle and pull the carpet up to get to the wiring harness, but that doesn’t mean you have to take the car to the dealer. You can either do this work yourself (pulling the carpet back will probably be easier than removing the sensor from the exhaust pipe, actually), or if the thought is intimidating, any reasonably competent mechanic can easily do this. I also suggest getting an OE replacement sensor rather than the cheapest available “make your own oxygen sensor” kit. I’m not a big fan of these universal sensors that require you to reuse the original harness and splice it into the new sensor, hoping it works and is wired correctly.

Thank you for the advice

While I’ve never changed this sensor on that model Buick, I’m pretty sure you don’t go pulling up carpet to get to it. There would be too much liability if a manufacturer built a car with the potential for exhaust leak into the cabin like that. But when you’re down at your local auto parts store, if you have a choice of purchasing a generic sensor where you have to splice wires or paying a little more and getting an OEM plug, go with that, much easier and more reliable.An O2 sensor socket is useful for installing the sensor, but since you can cut the wire, any socket that fits will work for removing it. I’ve broken O2 sockets trying to remove stuck sensors, so I usually use a solid socket for removing them.

I’m betting on the connector being close to the steering gear. 7/8 wrench also works.

no way do you replace this sensor from inside the vehicle, it is replaced from under the vehicle. i personally have never heard of anything like replacing an o2 sensor from inside the vehicle. tester is correct this car only has one o2 sensor after the converter. and based on some of the other post i guess they make a universal o2 sensor where you cut and splice wires, never seen those either but would recommend staying away from them and use the plug and play direct fit. but then again i’m just an evil dealership mechanic, just sayin.

Not true!

Some O2 sensors have the electrical connectors run into the passenger compartment. The 2000 Toyota Camry is one of them. http://www.toyotanation.com/forum/103-3rd-4th-generation-1992-1996-1997-2001/382726-how-replace-downstream-oxygen-sensor-2000-camry-4-cylinder-gas-engine.html


@bennyandthejets and g-14classified, there were some Mercedes-Benz models that had the electrical connectors accessible only from under the carpet.

tester i did not say it wasn’t true only that i have never personally heard of it but it’s all good, I never mind learning new stuff, that doesnt mean i dont think it is stupid. but the engineers dont ask for my input.

The engineers didn’t ask for my input. But I still have to fix it.


it just seemed as if you got defensive about my post with your exclamation point and wanted you to understand exactly what i said and not take it to mean anyhting other than what i said.