i had the same problem, i found a post here about somebody saying to take the O2 sensors apart and clean them with a spray cleaner i can't remember what i used, but it worked, now i don't have a check engine light and it's been good for 3 months.

 

02 sensors? Where are they located so i can clean mines? Could this be the reason my car doesn't start sometimes? My check engine light used to come on and go off frequently. But now it's come on and stayed on.

 

Thank you for your input. Will try it.

 

Just a thought...since all these codes are circuit low voltage and croped up after installing the new sensor I suspect you have a wiring ground issue. The brown and green wire is a common ground for all the sensors, it runs up to the ecm and is term 46. Check the last work you completed.

 

I think i am going to re-do the wiring just to make sure. thanks

 

What do u mean by term 46?

 

Sorry, terminal 46 is the specific wire that is in the ecm wire harness, right next to your battery is the computor/ECM with a large wire harness plugging into it, in that harness is the ground wire for the ground for the O2 sensors, the ecm has very small numbers on the plug. But, before you go up there, first check your work on the new O2 sensors. The fact that all 4 sensors show low voltage indicates you have a problem common to them all, also check the fuse #39, a 30 amp fuse right in the area of the ecm, this fuse powers the heated O2 sensors.. possibly it blew but I doubt it???the fused wire and the ground wire #46 is shared by all the O2 sensors.

 

I will check them and let you know what happens. Thanks

 

I cleaned my old o2 sensors with electric parts cleaner or you can use mass airflow/carb cleaner/throttle body cleaner which you can get at auto zone or walmart or other stores take the sensors out clean and dry them and then replace and have code cleared or simply take neg bat cable off wait a few mins then re connect but doing that will reset windows and sunroof id suggest auto zone they can check/erase codes for free and wont mess with window and sunroof settings I know how expensive a direct fit sensor is i have found an ngk direct fit cheaper at www.summitracing.com

 

Thanks. Will look into it.

 

Hey Frank. No luck on re-doing the wiring for those o2 sensors. I re-wired both sensors and took it for a spin and the light came back on. I haven't yet gone to Autozone to see what codes come up now but I am sure I will probable have to go with the direct fit O2 sensors. Could the fan not working have caused my two previous codes? The p0133 and p0154? In a previous post I had explained that my fan was not working and someone suggested i check a 30 amp fuse in the ECM. The one under the harness. It was blown and I repalced it and now the fan works fine. Any further suggestions? Thanks for your input.

 

Well I went and got the codes and again they are the same one p0131,p0137, p0151,p0157. All low voltage. I re-did the wiring. I am at a loss. please help.

 

Could the wires touching or being near the exhaust manifold draw current from them giving me a low voltage?

 

you dont want the wire touching the exhust system. Is the car new to you and you dont have any history on it? From your first post it sounded like you had one sensor out, replaced it then all 4 are now giving codes.??? In the coolent fan fuse area you were in earlier, fuse 39 is for the heated o2 sensors, may want to check it, just to reiterate all of your splices on the replacement are good? When did all 4 crop up??
Just for info are there any problems with the engine, vacum leaks etc.??also are all of the secondery air pump parts in place, all hoses , vacum etc. These hoses are in front of the serp belt....runs left to right...1in in dia. The pump is under the LF headlight area, may have to pull the wheel well out, but you should hear it run shortly after start up. The problem is common to all the sensors so it has to be a wire and circuit problem. Go to your dealer and ask to copy a page out of their book for this code, any one of the codes will do as it will show the diagram...all the codes address the same thing except they isolate the location, your problem is all are effected.

 

The car is used, I bought about three years ago. What happened was I hade the two previous codes p0133 and p0154, basically saying that the front two sensors were not good. I tried to clean them like someone posted earlier but to no avail. I purchsed two aftermarket ones, universal type for $35 a piece. Cut the old ones out and spliced the new ones in. Cleared the codes and drove around for an hour until chk engine light came back on. took it to autozone and they scanned it. this time $ new codes popped up, the low voltage on all four sensors. I then de-did the wiring again, making sure that I had a tight connection but it didn't change the codes, same codes, low voltage. I did check the fuses in the ECM and they are all good except the one related to the fan. Changed that and now the fan is working like it should but i stll have these codes, low voltage coming up on all four sensors.

I do hear the pump at start up so i know that is working.

I am wondering if installing sensors that are not OEM or maybe a wrong sensor will set them all off. I ordered a sensor for the cadillac but i am wondering if maybe the sensor is the wrong kind. Ironically the first two codes, well they are gone. What do u think about the sensors being the wrong ones? Thanks for your help.

 

I would highly suggest using quality sensors. $35/ea sounds really cheap. As PEETYZ suggested, the NGK ones at www.summitracing.com will work well. I installed one and have not had any trouble since. It was around $80 and a direct fit. OME was $180 or so for the Bosch. Could be a fault in the wiring harness. If you have the old sensors, pop them in the front again and see if the 4 codes pop up again or just the 2.

 

Just purchased two sensors from Summit for 150.33. Direct fit. I will keep you posted as to what happens. Thanks for all your help.

 

Yeah, I just realized that all i probably had to do was clean them and it would have cleared. I think i might have had a faulty gas cap if you ask me because it started one day when i put bad gas in it.

 

Hows the new sensors working out?

 

I have to wait two weeks for them to come in. I will keep everyone posted as to what happens.

 

Hey everyone: I want to thank everyone that help, with their knowledge and expertise, on helping me trouble shoot my problem and get it fixed. I FINALLY PASSED INSOECTION!!!!!!! tHANKS!!!!!! I finally passed inspection with the new O2 sensors from summitracing. They were a bitch to get in and I did have to wait 2 weeks for them but in the end they were perfect. Each part was $70.00 and it was well worth the wait. Again I thank evryone who helped.

 

linopizzolanti do you have that part # for the o2 sencers having the same prob.

thanks, joey

 

Bookie,
Drive it by Autozone and they will read the codes and give you a prinout with the codes and an explanation of the codes.