Sevensix9

Soo... for the past month i've had a problem, on stock tune and my trifecta tune, when driving normal (tune off) under WOT I would hit 20-24 psi depending on when I let off the gas. I tried flashing back to bone stock and the problem continued, I pulled everything apart and found some oil residue on my hot side. Well today leaving the house the car just wants to buck and jerk at cruise speeds, under WOT it sounds like a machine gun at 5K RPMs and up. I'm at a loss as to where to start, I replaced the #4 coil pack 2 months ago. before I drove her today, yesterday she ran like a champ.

-Alex

09CobaltSS1

I would probably start with the cleaning both the map sensors and the maf as well. After that, disconnect the battery for a few minutes, and see what happens.

Chevycobaltss3

iTrader: (2)

When things usually jerk and etc, it will set a code, wether its pending or not. First thing: look at logs if able, second Check your codes, if none, check maps like above stated, Look for boost leaks and etc. If none then check for water, oil in charge pipes if maf relocate, since that will make you stutter. Now if all good, compression and leak down test!!!!!! If you have a cylinder 10-20 off check that injector seal!

SSlobalt

Definitely check for codes, but the machine gun fire at 5K RPMs sounds like the injector seals. Let us know what your codes are.

montecarloman

What kind of spark plugs do you have? Had a 4 door TC come in missing intermitantly. I found E3 plugs in it. A new GM spark plug set fixed the problem.

Sox-Fan

iTrader: (7)

Trade it in for Fiat. Ass.