As many of you are aware I've had a very bad misfire problem for some time now that I cant seem to fix. I was talking to someone the other day and they suggested (with confidence) that it is probably my alternator. I didn't think an alternator could cause a misfire, am I wrong? I thought as long as my battery was still being charged, that meant that my alternator was fine?? For new readers, here is what's been done so far: Fuel System New fuel pump FPCU bi-pass (no change) Change injectors Fuel filter has done only 1500km Ignition System 6 new coil packs 2 new AFM (now back to OEM) S2 PTU x 2 CAS swapped in another one (no change) All electrical connectors cleaned and checked Other New engine, turbos, radiator and hoses (boost tested - no leak) New copper plugs (no change) Replaced ECU ECU not throwing any errors TPS (checked and fine) New Coolant temp sensor Air/Fuel mix altered by 5% using Conzult (up and down) - both made problem worse Symptoms Car starts first time every time and idles well. Quickly then develops a misfire that can be heard best through exhaust. While warming up car is almost un-drivable, struggles to get revs up under load. At about 4500rpm it starts to pull again and then boost comes on and your off (at least until you change gear ). This state improves the hotter the engine gets until its presence is only felt in the lower revs as low power and lack of response from the pedal when the engine is at 95 degress Celsius. (Yes I know that's a little high but I have another clutch fan coming soon). She usually runs at around 85degrees Celsius. I've just pulled the loom back from the PTU to inspect wires etc and couldn't see any issues at all there (relocated PTU at the same time). Next I'm going to do the same with loom going to ECU. The car has an engine immobilizor and is most likely spliced into the loom near the ECU. Does anyone know if the immobilizor could be the problem? I thought they were either on or off?? Now for those of you with a weak stomach ....stop reading because I'm going to start begging :bow2:. Somebody, anybody please help me!!!!!:lame: Seriously, I've had this car for two years and it's only been running properly for probably one week during that time, so I'm willing to listen to any suggestions no matter how ridiculous.