I just had a set of shorty headers (hooker competition series) ypipe and magnaflow cat back exhaust installed on my car, but now when i am approaching about 4800 in 2nd or 3rd gear in my 87 305 tpi, it acts like im hitting fuel cutoff or something... could this setup have changed anything enough that i need an adjustment of my PROM or maybe i need bigger injectors?? (still have stock 19LBs) help!!!

 

Check your spark plugs and spark plug wires. When I was changing out my header gaskets I broke the core on two spark plugs and didn't know it. I had a problem similar to yours.

 

I've broken plugs plenty of times when putting in or taking out my headers. You have to look very carefully at each one too. Its just a hairline crack in the porcelain. One of the easiest ways may be to wait untill night time. Get the car somewhere that is extremely dark. Turn the car on and look for blue sparks.

 

ill check it out tonight.. it couldnt be spark plug order could it? because when i had mentioned the issue the mechanic said he may have gotten the two plugs on the driver side closest the firewall mixed up... but it drives fine not rough i think i would notice that more right?

 

It would run rough at idle if they were mixed up. However, it never hurts to just go check.

If the mechanic said he may have gotten them mixed up, then that means he let the car leave knowing there was a potential problem with it. Wether this turns out to be your problem isnt the important part. I would find someone new from now on.

 

The new system could be just not flowing as well.

When I made a side pipe [yes pipe V6] the simple 90* tunr out totally killed the upper RPM band like that, knocked a hole in the end of it so it could flow straight out and back to normal fast n ahrd to redline.