Hey guys,
i have a 2003 coupe non revup and i have, test pipes with full custom striaght pipe with a high flow res, plenum spacer 5/16, nwp throttle body kit, oil cooler, oil catch can, and road tuned with rev up by on point dyno here in toronoto. I started up my car today going to school, like normal, drove the car yesterday like normal, but it started but misfiring, my plenum is tight and torqued down to spec but the only code i ran on the odb was p0507 which is the idle air control which i have been running since i installed this thorttle body tried doing the relearn 10 times brought to my buddy who was a tech a infiniti for 25 years and he tried doing the learn through his 2 obd's and didnt work either, let me know what you guys think, am thinking might be the coil packs and spark plugs

 

Pull all the plugs and inspect them, misfiring cylinder is usually really obvious. Inspect coil pack for blistering on the epoxy resin top (flat shiny part) and scorching on the spark plug well shaft, and corrosion on the spark plug contact spring inside the shaft. Ohm out the coil for spec. Replace broken components.

 

Thanks man ill give it a try