I installed Jet-Hot LT headers 2 months ago and they've been nothing but trouble. Here's my list:

-Running rich (Working with MAFT to correct)
-O2 Sensors setting off SES light (Still NOT solved)
-Y-pipe banging/K-member rubbing
-Jet-Hot coating rusting
-and the latest...I'm now missing in all cylinders on the driver's side.

It's the last problem that's got me really frustrated! Here's what I've done so far to diagnose it:

-Replace plug wires
-Replace plugs
-Swapped coils around to see if I could make the problem "jump" to another location.

The problem is still persistant. ATap says that I'm missing mainly on the driver's side cylinders, with a few on the passenger side, but not many. The primary offenders are cylinders 3, 5, and 1...7 isn't as bad, but it does miss as well.

I guess the next step is to look for a burnt or pinched wire, but can anyone tell me where the wires that power the coils primarily run? I do have a set of wires that run VERY close to the header on the passenger side. Does that harness contain any wires that have to do with the coils? Where do the ground wires ground for the driver's side coils?

Any and all suggestions on what to try next would be very much appreciated.

 

One other thing, since my O2's aren't acting right, could this problem be related to my O2's? Bank 2 is throwing the "Insufficient Activity" code and Bank 1 is throwing the "Insufficient Switching" code. Would that have anything to do with my miss?

 

Make absolutly sure you did not cut/burn/pinch any of your wires for the O2 sensors

Replace both of your O2 sensors and your plugs all at once.

One or both of these suggestions should clear up your problem.

Josh

 

I had a new thought. I already know my O2's are bad, but I keep resetting the SES light with ATap, so the car never has a chance to revert over to the preset program that doesn't look at the O2's. I let the SES light come on and then stay on and went for a drive. It ran better, but since I did a computer reset yesterday as well, it's having trouble idling. It is still missing at idle, but I watch the RPM's drop to as low as 700 and then the misfires happen and the coputer revs the engine up to around 1200 RPM and lets it settle in to around 800 RPM or so. It gradually drops down to 700 and repeats the process.

I also noticed that I don't have a miss at WOT, but the computer doesn't read the O2's at WOT, so that's another reason I'm thinking I just need to leave the SES light on until I replace the O2's.

Does all of that sound like a possible explanation? The only thing I'm worried about is I have now let the car idle for 5 mins with the air off and then again with it on, and it still has the idling problems.

Can headers cause idling issues?

 

You need to go back over your work and look closely at the wiring. Did you damage something during removal of the exhaust manifold or installatin of the headers? Were you careful with the wiring harness during installation. FelPro makes a wide variety of heat resitant insulation for wiring applications that run near HOT exhaust pipes. Go visit NAPA. It pays to be EXTRA careful when installing your headers, but if your careful and watch what your doing you shouldn't get into trouble. At what point do you first start getting these DTCs. That should help you isolate where the problem is. Also the 1,3,5,7 thing is starring you in the face.

 

I got my 1st DTC about a week after I installed my headers, but I hadn't driven the car. My 1st DTC was "Insufficient Swtiching" for both O2's, now I'm gettting "Insufficient Activity" from bank 2, so I'm fairly sure that sensor is now dead...I've gotten the "Insufficient Activity" from bank 1 as well, but it's still going back and forth between "Insufficient Swtiching" and "Insufficient Activity" so I'm sure it's not far from being completely gone as well.

I examined the wiring very closely today. I'm 99% sure the headers aren't running close to any wires that have to do with the coil packs. The only wires that run dangerously close to the headers are on the passenger side, and those are the O2 harnesses for the Bank 2 O2 sensors. I agree that the 1,3,5,7 starring me in the face does indicate a common problem, but I've made a couple more observations today with ATap.

-I don't have a miss when I'm at WOT.
-The SES light came on and this time I let it stay on. I didn't notice a miss once the computer switched over to the programming that doesn't need the O2's.

After I turned the car off and let it set a little while and then restarted it monitoring with ATap, the miss was in all 8 cylinders at one time or another, no longer 1,3,5,7 the majority of the time.

All of this leads me to believe that my problems are stemming from bad O2 sensors. However, I have one BIG question:

Even with the SES light left on, IF I let the car sit and then come back later to check things out, the car doesn't seem to miss for the 1st couple of mins. (the computer doesn't check use the O2 readings until the sensors reach 600F OR 2 mins. of run time, whichever comes 1st) but then I have the miss for a while longer, unless I go for a drive in which the computer has time to check the O2 readings, and then my miss goes away. So my question is: Even thought the SES light is still on, does the computer still check the O2's just like when the SES light is off, until it can determine if it can rely on the O2 readings, or it needs to switch over to the preprogrammed settings that disregard the O2 sensors? Does it go through the same sequence every time, or since the SES light is on from a previous drive, is it supposed to automatically go back to the preprogramed settings?

For now, my next step is to replace the O2 sensors to see if that cures my problem, and if not, then I've got to investigate further. Can O2's wreak this much havoc?!

 

Considering the computer takes the O2s into consideration in nearly all situations (except WOT), yes, they can cause that much havoc. Just replace them, then see what changes. If the O2s are screwed, car could be running super rich or lean, and causing misfires.

Dope

 

It's definitly the 02 sensors.When you get a 02 switching code ussually a misfire will follow because the computer loads that bank with fuel.Replace 02's ASAP because it's loading fuel in the cylinders that can cause fuel wash,then correct your tune.Also don't let the car idle for long periods of time with longtubes.