Fade2blk500

iTrader: (18)

After putting headers on a 01 ss, it developed a bad miss. The SES light is flashing and its running like crap. I tried unplugging the 02's and running it but it doesn't do anything. I looked all the plugs and wires down and they appear fine. Could it be the stock tune? It's running a magicstick vs 3, prc duals, and longtube headers. The car is also running open headers..

Thanks
Craig

sdbrown84

iTrader: (22)

Make sure you still keep in your front O2's and run sims on your rear O2's. If you don't have your front O2's in the PCM will instruct the car to run at a bare minimum because it can't calculate the A/F ratio.

Fade2blk500

iTrader: (18)

front 02's are correct, rear 02's have simulators. i'm about to go out and troubleshoot this. any more suggestions?

Tally TransAm

iTrader: (17)

recheck all the plug wire connections and the coil pack harness connection

im better you left something loose

Fade2blk500

iTrader: (18)

Update, pulled the plugs and they are completely black, running WAYY rich. mounting up the y pipe tonight and changing the o2's out. This thing DEFINITELY needs a tune!

The Alchemist

iTrader: (19)

If you are running open headers, the problem is you are pulling air back into the O2s causing a false lean condition. In turn, the computer is dumping more fuel to try and correct the situation, hence your black plugs.

Did you install the plugs after you bolted up the headers? If not, you may have cracked a plug and not even know it.

Good luck.

Fade2blk500

iTrader: (18)

Got it fixed! mounted the y pipe up, pulled all the plugs and cleaned them up. Fired it up and it idled!! Drove it around a bit. Alot of bucking/surging at anything less that 2000 but that's mainly from the stock tune. It feels like it's running better the more I run/drive it.

~JOSHUA

iTrader: (92)

What he said.

MetallicaMatt

iTrader: (19)

quick question,

i'm runningin w/o cats. but i don't have O2 sims, I am going to have them tuned out. I hope to beable to start the car tonight. will I be okay w/o O2 sims? She'll just run rich right?

c1823a

MetallicaMatt, if I understand all this correctly, you only need O2 sims for the rear sensors. I think these rear sensors only monitor the efficiency of your catalytic converters and turn the SES light on when they're not up to par. I don't think you'll run rich from the rear O2's not being installed, you'll just get the SES light. I could be wrong, though.

MetallicaMatt

iTrader: (19)

i started her up tonight, idles a little different. almost idles lower? No sims or nothing, no SES light. Though I didn't drive it, only let it run for 20-30 minutes

natronathon

yeah, the rear o2's do not affect any performance or fueling. They simply monitor the effictiveness of the cats. The front o2's are the ones that do all the work! For future reference, keep the rear o2 sensors, as they can be used to replace the front ones when they go out.