MonsterParadise

iTrader: (4)

I have idle problem since I bought my car, but it just moving from 800-1000Rpm. Usually, when it jumped up and down, I just gave it alittle gas, then it became normal. After retune today, when I cool started my car the Idle was normal, but when it got hot, the idle jump up and down from 1000-200 rpm for couple times and the engine turn off every time at the stop site, red light, or when I started my car with hot engine. Check engine light come on with the code is PO300 "Unknow missed fire". I have to clear the code 4 times since I left the shop( my tuner spend 2~3 but couldn't find the problem). Is there any thing that I need to check? Any wrong with spark, or fuel injectors,... Please Lmk what do you think. I just want to have it fix. This is my mod list:
Arc: FMIC, UICP, Intake box.
Ams: 02 downpipe, UR HFC, SpecialtyX catback.
255 fuel pump with DW1000cc injectors.
Thanks
Anh

gsrboi80

iTrader: (38)

Ignition components, Idle timing too advanced, large gaps between timing and fuel cells, improperly scaled fuel injectors, all can trip an P0300