Whats up guys? I need your help, I have a 95 s14 with a S13 sr20det. Fmic, everything else its stock. This car when it warms up it starts to misfire and its also running rich. Now the IAC was changed along with CAS and all 4 coil packs and O2 sensor was changed and she still misfiring, keep in mind im not doing the work its at my friends shop, but i also wanna try and help them find this issue so i can enjoy my toy like a little kid. Thanx guys.

Check MAF...
Check fuel pressure regulator...

The MAF has been cleaned and still the same thing, But when you unplug the MAF the car idles fine no misfire at all, im trying to see if I can find a MAF just to try it out, I got an N62 but its not gonna work with my stock injectors and stock stuff. Ill check the fuel pressure regulator.

Ok the fuel regulator is fine, now the misfire is not as bad, the guy said its more like a detination issue, but now the car if you keep your foot on the gas at 4000rpm it starts to break up, puttering. And they cant seem to find the promblem if anyone can think of anything please help.

this may be stupid as its usually the first thing id check, but have you checked the spark plugs? i know with the rb's they like to be gapped pretty close. i think mine are at .25 or somthing like that. but id definatly check that and its a pretty easy thing to check. and the fact that your saying it runs fine with the maf disconnected but has issues when you connect it tells me that the motor is seeing extra air so check for vacuum/boost leaks.

Thanx for the reply. The spark plugs are new. Motor wise its perfect, but its just that stupid issue. The MAF is fine. We looked for leaks and cant find anything.

Check all Ground connections, check your fuel pump, and just for the hell of it try another maf,sometimes they are messed up when you think they're fine.

New plugs are nice but what are they gapped to? Try downsizing the gap.

Thanx guys. I will check it on saturday and keep you guys posted.