: Oxygen Sensor buying help - Code P0155

11-15-06, 10:26 AM
Hey everyone:

I have the P0155 code, 02 sensor Bank 2, Sensor 1. I'm sure not which oxygen sensor to order as there are multiple types. Does anyone have a part number or can describe the right one? I'm confused!


11-16-06, 02:43 PM
I've called my 2 local Cadillac dealers today and they don't have a clue! I think the most important info to know is if this is before or after the catalytic converter. Any ideas? HELP! I have a service manual and am still stumped!


11-16-06, 03:54 PM
CateraSport2000, go to an Auto Zone if there's one near you. They check codes for free and can narrow it down for you. Also, did you do anything different to your Cat to make that code come on? The reason that I ask is because when I first bought my Catera I mistakenly put in an octance booster that contained MMT and I got the same code. I believe that it's the 02 sensor closest to the converte. Before you go and spend a few hundred dollars on it, try this: first, take it out and clean all of the 02 sensors. I almost everyone says that this can't be done but it can. Use a CLEAN wire brush, the kind that is the size of a tooth brush and some carburator cleaner. Have Auto Zone or whomever clear out the code for you. Drive it around for a while; it worked for me.

11-16-06, 03:57 PM
That should say, "I know that almost everyone says that it can't be done but it can." Sorry for the typo.

11-16-06, 04:18 PM
I got the code by going to Autozone...that's what the code reads: Oxygen Sensor, Bank 2, Sensor 1. That's all it gives :(

11-16-06, 04:19 PM
Caterashaker...how hard is it to take out the oxygen sensor? Any special tools? Jack the car up?

11-16-06, 05:47 PM
According to the manual, bank 1 is the pass. side, bank two the driver's side.
Sensor 1 is before the cat converter and 2 is after.

Hope this helps

11-16-06, 06:03 PM
therefor replace your driver's side, before the cat sensor. they screw in and screw out.

11-17-06, 09:38 AM
Thanks for the info, you've been really helpful! I now have the part ordered from Rockauto.com ($126 for ACDELCO) and will try to put it in myself but may end up letting someone else do it if I can't comfortably wedge myself under there.


11-17-06, 11:46 AM
they sell a decent set of jack stands and a jack at kragen for only $20

11-17-06, 08:48 PM
todd2fst4u, $126 is actually not a bad price but did you do something to make that light come on? How many miles does your Catera have on it? By the way, if you decide that you want to change it, when you put the new one on, it may or may not have some high heat anti-seize on it; make sure that this stuff stays ON THE THREADS. If it doesn't have it on, I would suggest putting some on. How long have you had your problem?

11-18-06, 07:58 PM
Be very careful. I just attempted to change one of my o2 sensors, and the threads in the pipe came out with it! Now I have to replace that whole piece of pipe. God these cars are a pain!