don't know if this has been covered yet due to the fact i havent been on here in a while. so if it has then flame away and i'll go to a corner and sit and think about i've done! as many of you z owners know they are real bastards on cold starts, low idle, stalling, surging and all that other crap that makes you want trade it for a honda (yeah right) i've talked to guys that have spent countless time and money on replacing sensors and god knows what else. it seems to have somthing to do with back pressure. my car was the worst for that @!#$ untill i installed my header and 2-1/4" exhaust. hasent done it since! any input on why an exhaust upgrade fixes an
idle problem would be appreciated!