Got done installing my new Pacesetter LT's and X-Pipe a few days ago and cannot get the car to run right. Car stared missing and backfiring randomly through the exhaust. So I figure the o2's got messed up from the crap burning off the new headers (reading between 400-600 on scanmaster after warming up) So I pulled the plugs ALL BLACK, so I changed them, gapped correcty. Made sure all the wires were good, and as a hunch unplugged the o2's. Car ran awesome for about 15 seconds and whap starts missing and backfiring again.



Any idea WTF is goin on?




Opti has about 8K on it if that
new wires
new plugs
fairly new ICM and MSD Coil
Digital-6
Walbro 255lph Pump

What you guys think?

 

02's

 

I dont see how it could be o2's if they were unplugged the second time around......

 

Dude, now you got me scared with installing pacesetter LTs on my car. Where are you located? I know a guy that will sell a used working opti for $50 bucks. Maybe it would be worth buying so you can eliminate that possiblity, even though it's pretty new.

 

Typical problems with an install like this is:

-contaminated O2 sensors
-poor quality O2 extensions
-high voltage wire near the O2 wires
-header leaks before the O2 sensors
-misfires due to damaged wires or plugs.

When you disconnected the O2 sensors, did you also reset the PCM? If not, the BLM's that were "learned" with the possibly defective O2 sensors are still saved in the PCM, and stil being used to run the engine.

 

Thanks Injuneer, I'll give that a try after work.

 

Just pulled the passenger side plugs, 2 and 4 are covered with unburnt fuel, 6 and 8 are black but look to be firing. Time for the Driver side.

 

Update, re set the computer like injuneer said, installed new plugs. and.....







Car runs great!!!!!



So i need o2's

 

Read my original list. The PCM is getting bad data from the O2 sensors. It could be anything on my list.

 

Next time listen to me.

 

what do you mean by resetting the pcm. just disconnect the battery for a few seconds? this is probably a stupid question.

 

pull the pcm batt fuse for 30 sec