Unchainedl984

Hey, i'm new to this forum and I've got a question about one of the o2 sensors. I've got a 99 LS1 Trans Am and last night after i got a Service engine soon light. I had my foot into it, and the light came on right after so i got kinda worried. The light went off later that night, but I brought my car to Autozone to get scanned today and the code p0157 came out. He said it was one of the o2 sensors after the cat.

What i'm wondering is, is it hurting performance at all? Like I said, its after the cat so i dont know if it affects the air/fuel ratio info going to the engine. If its hurting my mpg/performance then its easy enough to replace, but the light went off and if I wont get any benefit out of replacing it is it worth it?


Thanks alot

RARON455

iTrader: (35)

Not hurting the car being after the cat, If you plan on replacing them, You might want to consider removing them, and having them deleted thru a mail order tune, You will gain a lil power, and if you ever want to run the car with an ORY pipe setup you wont have to worry about throwing codes. and the tune is close to the price of replacing the sensors,, Hope this helps.

Darkman

iTrader: (2)

That code can also be caused by temporary lean condition, water intrusion in the harness, or vacuum leak. If it doesn't come back, I would not worry about it. See attached.

Unchainedl984

Ok cool, I was hoping it wouldnt really affect anything being after that car. I'm definitly planning on that someday. The cars stock for right now expect a lid & a muffler, but I want to start modding it. I know the best thing to do first is an exhaust, I want to throw some headers and an ORY like you said but for right now the car still has to go through emmissions and I dont think it will pass with that stuff.

On another note though, any advice on some cheaper mods that I might see some gain out of with the stock exhaust manifolds?

Unchainedl984

Thanks, it was probably something minor like that that just tripped it up temporarily. Was pretty relieved to find it was an o2 sensor though, I really had it up there doing a couple WOT runs with a Cobalt SS and the light came on right after so I thought something gave out.

mannyman84

iTrader: (2)

Rear o2's are just there to monitor the cats. Front o2's are the ones for your air fuel ratio. What was the exact wording for the code? Was it slow response? Heated circuit? Or what was it? If it's heated circuit all it means is that the circuit to heat up the o2 sensor is dead. If u don't want to replace it u don't hve to. Just that the light is annoying. Haha.

mannyman84

iTrader: (2)

Plus o2 sensors are ignored at WOT so this must of been a pending code from before and PCM finally decided to turn the SES light on.

wssix99

iTrader: (5)

Was your engine up to temperature when all of this went down? If your cats weren't hot, then they won't be able to properly handle a full load. If that's the case, then its fine for the car - you are just killing little forest creatures with your noxious fumes...

Unchainedl984

yeah, engine was up to normal temp, I always make sure it it warms up before i put my foot into it lol. I appreciate the help guys