All,
Just finished up installing Pacesetter LT's and TSP True Duals complete with O2 Sims. Install took a couple of days since I was only working on it after work. It rather smoothly, but now I have a very noticable miss when getting into the throttle. Sounds normal at idle, but like I said once I get into the throttle miss is quite noticable. Everything was fine before, so I am hoping it is something simple. I have tried the obvious, checking the plug wires, etc...but can't find anything out of place. And I have no SES lights on.

Thanks in advance guys and any help would be appreciated.

 

A spark plug may have a small fracture. Have you checked all the spark plugs? I had a spark plug with a really small crack in it and my car ran till about 2-3k then it would start missing.Could be something with the sims. The rear 02s can be out for a couple of days till you have a ses light.

 

do the plugs have screw on tips? reason i ask is because when i did my headers a year ago, i had the same problem.no ses light-nothing but a dead miss under higher rpm load. remove your plugs and make sure the tips (where the wire goes to) are on tight. also, something my friend did, when all the plugs are out, recheck the gap. my friend collapsed the firing tip on the rear plug of the passenger side. it fired normally at idle and soft loads, but under a heavy load it missed. double check.
hope this helps, good luck

 

Change your plugs. I got an entire box of bad plugs one time(think it must have been dropped) and at the time you could have never known there was anything wrong, but at certain rpms it was misfiring. I checked the plugs seemed fine. About 300mi later I replaced all my plugs, and when taking out one side the ceramic just disentigrated

Anyways, change your plugs. It is cheap to do, and not that time consuming.

 

Thanks for the resposes. This morning on the way to work the SES light came on. So at lunch, I went to autozone for them to scan the code. It showed a misfire on plug #7. So when I got home, I removed the plug and sure enough it was cracked in the ceramic part from top to bottom. Changed the plug and now it runs like a champ.

 

cool, glad you found out what was wrong.

 

I had the same issue when swapping headers... cracked the plugs and I was very careful when removing and installing the headers.