I threw a code, and I am not understanding why? I just replaced the darn o2 sensor like a month ago, and now it is saying no activity, all the wiring looks fine, but I dont understand why I would be throwing this code? I put a multi meter on it and it said I had .19 volts? The guy at advance said it should be 12 volts? Is this correct? It is the front o2 sesnor by the way and it is a crappy bosch... Any help is apprecaited! Mainly, what should the voltage be on the bank 1 sensor 1? I did it with the key turned over by the way, so I know the volts are accurate. ANy help, Please! I need to get a sticker in the next week and need this fixed!


98z24, lowered 2", aem intake, cat-back striaght pipes!, cop ligths in the front and rear, 18" liquid metal's, primer black, tint, full audio and video.

I also forgot to mention I had another code be thrown, it is for my speed sensor... Where is it located? I cant remeber the code, P503 P504 something in that range, but where is it located so I can replace it as well.


98z24, lowered 2", aem intake, cat-back striaght pipes!, cop ligths in the front and rear, 18" liquid metal's, primer black, tint, full audio and video.

well, after looking at some pics online, I have made the assumption that my speed sensor is the one that has 2 wires connected to it on the underside of the tranny, right? I have a M/T by the way. SO I got that figured out, but what is the wire that connects to the bank 1 sensor 1 o2 sensor suppose to read? 12 volts? .19 volts? .5 volts? What? Haha!


98z24, lowered 2", aem intake, cat-back striaght pipes!, cop ligths in the front and rear, 18" liquid metal's, primer black, tint, full audio and video.

Your O2 sensor reads in millivolts. It should bounce between .100-.900mv. It could be the sensor. Also sensor could be good, but wiring connections could be bad. If the ECU does not see the signal it is a issue.



FU Tuning

Thanks alot! And I dont know if you remeber it or not, but what stopped my saga of hesitation and sputtering ended up being my o2 sensors, I changed to a bosch and had the problem, when I put delco ones in there (way expensive by the way) it cured it... Thanks for all your help about a month and a half ago! You are the man! And I think it was reading in mv's, that was my bad about .19 volts. So I guess all is good, and after I disconnected the battery, the code went away! So all my whoes are finally cured!


98z24, lowered 2", aem intake, cat-back striaght pipes!, cop ligths in the front and rear, 18" liquid metal's, primer black, tint, full audio and video.

i had a friend back in the day had the same thing happen. had a faulty stock o2 sensor, put a bosch in, same code came up a little while later.


best advise is yes to stick with ac delco. i dont use bosch anything really. never had, or heard many people having good luck with their stuff .

I will say I have always said use a AC o2 sensor (especially when replacing stock parts). Funny thing is I'm currently running a Bosch heated O2 sensor on my 01 with no issues. This was so I could install a heated one. I still believe in the AC stock parts. I have also seen times when installing a new part does not fix the problem right off until after a ECU reset (like disconnecting the battery for 10-15 minutes.



FU Tuning

Yeah, but I have definitely reset it PLENTY of times since the change! Haha! But I must say as well, ALWAYS use factory replacement parts when replacing sensors and such, it will help you out in the long run, atleast this is true in my case!


98z24, lowered 2", aem intake, cat-back striaght pipes!, cop ligths in the front and rear, 18" liquid metal's, primer black, tint, full audio and video.