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Cylinder Misfire
Thread Starter
Joined: Dec 2004
Posts: 1,685
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From: Lake In The HIlls
Cylinder Misfire
Today I was driving and all of a sudden threw a check engine light when I boosted. I took the car to Murray's and threw the P0304 cylinder number four misfire code. I exchanged cylinder number four spark plug without deleting the code but still no luck. The car idles perfectly fine when I start it up but once I rev it (sitting still) past 5k, the idle becomes terrible as if it is about to die. Also, when I am driving and decide to boost the car works flawlessly but say I downshift and boost, the car starts sputtering. I don't know if this can be a problem but I installed a Walbro fuel pump last month without a tune and the car would hesitate sometimes. Feedback would be greatly appreciated! 
possible hole in the coil boot. i had same issue and that is what i had. there will be a small tear in the boot itself. the spark should be coming out of the boot so a white residue should be vissible. check into it for real evos are known for this.
