Ok so I resently installed an exhaust manifold, O2 housing, downpipe cutout and new plugs. When i start moving it sounds like im running on 3 cylindersand after like 2500-3000 rpm the car runs normal. Also when I hit about 16 psi and on it starts breaking up and ****. It threw a random multiple misfire code. Tring to fix the problem i replaced coils, wires, and plugs. Still doing it and im afraid to drive it.
My battery dies very fast if i leave the car not started with the lights on. Will a bad battery be causing the misfires?

 

What'd you gap your plugs at?

Battery= posibility

 

its not the gap i have em at like 22-23. Any other help!!!???

 

vacuum leak possibly around one of the parts you installed

 

after first starting, does it run better than say after 5 mins. of running?

 

What manifold is it? Is that leaking? I would put stock stuff back on, till it runs good, and then you know the problem.

 

forget to plug in your MAF by any chance? I've forgotten a few times now

 

The MAF is pluged in and its not a boost leak i have a engine code for multiple random misfire. I changed coils and plug from my buddies car and it ran fine. The only thing i can think of is gettin new coil boots...ill let u know if i need any futher assistance. Thanks

 

Yes, a bad battery will cause this problem. And while you are at it, check your alternator to make sure it is running properly.

 

Do you have a pic of your coils ?
Do you have correctly tighten the plugs?
Do you tried to changed them? ( the old ones)
A worn battery would make harder engine starting but then the alternator regulates a 14V voltage

 

Do you have EvoScan (or another logger) it might give better insight as to what is happening.

Most will probably not agree, but I have a more conservative approach to mods and to me it seems like you might have changes too many things at once which might make it more difficult to track down.