I have a 98 TA with 95,000 miles if that matters. Well over the weekend i put on mac mids with flowmaster cat back (it was on the car) and ngk tr55 plugs with msd wires. I got the job done but it doesnt idles right. It idles fine for like 5 seconds then has like a little jolt or hiccup and then idles fine. When the ac is on it gets alot worest. I took all the wires off and put them back on so i am POSITIVE taht the wires are on right. I dont know what else it could be. I gapped the plugs at stock gap. I drove the car for about 30miles today and it drives fine if you baby it but soon as you give it a little gas it hesitates and feels like soemthing is holding it back. Then when it is in over drive and you try to excellerate it studders also. I did remove 2 coils but i put them back the same way they came off. No codes! Any ideas???

 

Unless something else has gone wrong but since there are no codes don't think there is. Check all your plugs and wires again and be sure that all your coils are plugged in correctly.

 

Sounds like an igntion problem. Like mook said triple check and wire connection that you took loose and maybe check for burnt wires, even though thats pretty impossible. If nothing else pull the plugs and check them again.

It's very easy to over look a wire not snapped all the way on a plug or coil and it will surely make you lose lots of power.

 

Did you hook up all of the emissions stuff? Might be a bad o2 that just isn't throwing a code yet.

 

if its not undriveable, give it like ~100 miles to learn itself with the new headers. that could be an issue

 

OMG if I hear another "learning computer" false diag I am going to scream!

On the L98, when the cars were "chipped" then you had a semi learning system that would take some time but was very limited on what it would learn.

With OBD I we get more learning.. its faster and learns as it goes.

Now with OBD II there is no real learning curve. Its instantaneous. Its why its constantly measureing the air intake temp and whatnot. So it can adjust on the fly. Adding a mod will not take some time for it to realize it. It sees it right away.

For the original poster, I am thinking you didnt get all your plug wires on tight.

 

Maybe you broke the porcelean on a plug so that it's not firing right.

 

ding ding ding - thats what i would put my money on if you still have emissions on it-

header coating tends to burn off and crap out the o2's - when mine were installed, car was allright at first but started having trouble idling. then car would stutter, and under throttle miss and surge like crazy and felt very weak. no lights were being thrown for about a week.