o2 problem please help

i got a ses light and i scanned it and it was p0157 bank 2 sensor 2 circuit low voltage. this was on friday and i took it to the dealer, they replaced it under warranty and then this sunday i got the ses light back on and i scanned it and i got the same code. i will call the dealer and tell them but one thing i was thinking was since it is an o2 behind one of the cats could this mean the cat is shot and the sensor is getting a bad reading? there are no codes about cat converter, thanks for any help

i got a ses light and i scanned it and it was p0157 bank 2 sensor 2 circuit low voltage. this was on friday and i took it to the dealer, they replaced it under warranty and then this sunday i got the ses light back on and i scanned it and i got the same code. i will call the dealer and tell them but one thing


i was thinking was since it is an o2 behind one of the cats could this mean the cat is shot and the sensor is getting a bad reading? there are no codes about cat converter, thanks for any help

Probably. And yes there are. Don't remember the # but it's "catalyst low efficiency"

i called the dealer and told them i got the code back and the service manager said they didnt replace the o2 because when they scanned it it showed the o2's were being set off at 123 mph and he wont let his guy drive that fast, now since these are set off at 123 arent they bad at 0-65 mph also?he said he tested them and they are fine.

when i said there are no codes about cat converter i meant i wasnt getting one.

Great timing. I too may be having o2 problems? I threw a SES light three days ago, got it scanned and it was 8 codes, all four o2 sensors. Figuring this is some weird fluk, I drove home to check the O2's, but on the way home the SES went off by itself??? Now three days later, when I thomp on it, it gets sluggish and seems want to die but hasn't yet. Do you guys think O2's here.

How the hell does a dealer check an O2 sensor anyway?

Great timing. I too may be having o2 problems? I threw a SES light three days ago, got it scanned and it was 8 codes, all four o2 sensors. Figuring this is some weird fluk, I drove home to check the O2's, but on the way home the SES went off by itself??? Now three days later, when I thomp on it, it gets sluggish and seems want to die but hasn't yet. Do you guys think O2's here.

How the hell does a dealer check an O2 sensor anyway?

Low voltage seems to point to 02 reporting very lean condition for a period of time.
A PCM scanner needs to monitor from a cold start to normal operating temps and see what the fuel trims are for that side.
Exhaust leaks, weak 02 ( older then 30,000 miles) would be the 1st things to look at if the fuel trims are within normal range

You can check an O2 by heating the tip up with a torch and measuring what the voltage ranges are.

Can an exhaust leak cause that? I just welded a flowmaster up about three weeks ago. There were concerns about a leak in the outlet weld. My friend did the welding so I wasn't going to bitch about it. He ended up using some gray goop to seal the leak...Since then this is the second ses I've had, the first being pretty much the entire intake system (like 6 codes, maf, tb, ect.) got them erased and it's been fine. Is this possible?

Sure any leak that can cause air to be sucked in or change the content and temp of exhaust gases will fool the O2.

Worse that goop if sucked in will corrupt the O2

Can an exhaust leak cause that? I just welded a flowmaster up about three weeks ago. There were concerns about a leak in the outlet weld. My friend did the welding so I wasn't going to bitch about it. He ended up using some gray goop to seal the leak...Since then this is the second ses I've had, the first being pretty much the entire intake system (like 6 codes, maf, tb, ect.) got them erased and it's been fine. Is this possible?

good to know. I'll get that looked at. Thanks for the insight

mine also acts weird at around cruisin at 60-70 it kinda seems like it has a slight miss or hesitation, if i use o2 simms for after cat area o2 sensors would that be ok?

yeah i just bought an ss and the day i bought it the ses light came on now im knda pissed since it has only 36k on the clock went to autozone and they said i was running lean(thanks a lot guys) that told me nothing then i went to my friends shop and we started figuring out what the problem is.the exhaust fumes are supposed to be cooler when they come out of the cat and we were reading the temps and it wasnt coller causing a sensor to go off (ses light) so i said screw it im just gonna order o2 sims but do you guys know if i can take the car back to the dealer to get a good cat put on since the one they sold me had a bad one and wont pass emmisions?

DON'T do the O2 sims. I havn't witnessed this, but I have read in multiple articles that o2 sims make more problems for these cars than their worth. Your better off replacing the O2's and leaving it at that. Thats what i've heard, correct me if i'm wrong.

DON'T do the O2 sims. I havn't witnessed this, but I have read in multiple articles that o2 sims make more problems for these cars than their worth. Your better off replacing the O2's and leaving it at that. Thats what i've heard, correct me if i'm wrong.
i plan on throwing on a offroad y pipe on so i will need the o2 sims so i dont get the ses light. unless there is some othere way im all ears? :confused:

That's just what I've heard. I haven't seen any proof, other than a few articles (which may be BS?) Get back to me if you do this and let em know if any problems occur.

im not being rude when i say this but you heard wrong, how else would so many people use orp with their headers? besides getting the rear o2s deleted from the pcm.

DON'T do the O2 sims. I havn't witnessed this, but I have read in multiple articles that o2 sims make more problems for these cars than their worth. Your better off replacing the O2's and leaving it at that. Thats what i've heard, correct me if i'm wrong.

Your wrong :)

The only time that O2 simulators cause a problem is when people put them for the front O2s instead of the rear (aftercat) O2s. The front O2 must be there and working correctly for the car to run right. The rear O2s just check to see if the cats are working or not and even if not working correctly have NO effect on the cars operation.

Like I said...Just what I've read. I havn't seen any proof to back it up. Around here that is all I've seen is people getting the PCM reprogramed for this mod.