I'm thinking plug wires. My car ran nice with no load on it and when it had any kind of load it would run like total garbage. Check for missing header bolts and header leaks but more importantly a wire that is burnt and is now arching. I burnt a couple wires and they were arching to the one of the header pipes. Problem solved.

-brian

 

What I would do is find another vehicle with the same MAF and try swapping them out first instead of just buying one. I don't know for sure which vehicles work but there are quite a few with the same MAF and I know some of them are full size PU's. Not like those are hard to come by.

 

if the car ran fine before the headers obviously it has something to do with that(plugs, wires, 02 sensors, sensor extensions), not the maf. but what do i know....

 

The thing that says this problem is with O2 sensors and not plug wires is that he says his car runs fine until it warms up.

If it were plug wires it would run bad all the time.

The o2 sensors are not used until the car is warmed up.

 

Are your headers long tube? Pacesetter dosn't include o2 extentions. Instead they give you a roll of wire to extend the o2's which is a horrible idea. When I installed mine i had the same problem after a few months and that was it. If this is the case buy new o2's from a gm dealer (part store o2's are junk and will cause problems down the road) and get o2 extentions which I bough through summit racing for like $20 each. This is a common problem and so far this is the best solution. I didn't read the whole thread so excuse me if I missed something but this is exactly what I went through. Good luck and I hope this helps you.

 

I just read the rest of the thread and it sounds like I was right. Casper electronics makes the o2 extentions I have and the 12" are long enough. Buy 2 of them and new ac delco o2's from a dealership. I promise you this is your problem. I've fixed this problem on several cars since it happened to me and it did the trick every single time.

 

denso o2's work better and are cheaper

 

Most people strongly recommend AC/Delco O2 sensors.

 

Today I ordered 2 acdelco sensors and 2 12" wire extenders once I get it we will see what happens

 

i got 2 denso's for 70 bucks...usually ac delco or denso are recommended just bocsh is definitely something to stay away from they are way to hit or miss

 

so what ever happened w/ this whip?

thread came up on a search.

 

I am thinking it is the plugs/plug wires and/or the o2 extensions. I had the same symptoms that you are having, and I got to tearing **** apart, and realized that it was frayed/fried wires and fouled plugs. +32432 on the AC Delco platinum. They are the ****, and are not that expensive if I remember right. For a street car, they will work great. Might as well go for all MSD wiring and AC Delco plugs.

 

93s dont use an external knock module

 

just installed my pacesetter long tubes this weekend and she cranked right up. Ran her around the block with open headers only with no pipes yet, man was i disappointed. Sure it was loud as hell but had no throttle response at all. Felt like i lost power. I know it was probably the lack of back pressure. Can someone verify this??? Also i have the drivers side O2 sensor totaly removed from the harness for splicing right now the car wont even start. does the computer recognize this as a error in the system and stop the car from turning starting up????HELP

 

We had a similar issue with a friends Z28, check and see you have the wires right on the opti it self.