banjolyn

Hello Everyone,

I bought a 06 Burb 6.0L about 6 months ago to build a camper truck out of it. This thing is a beast. Didn't have any issues when I bought it, except for an exhaust leak.

Hard start. Runs great for 40 mins, then a hard miss. It will get increasingly worse, sputters and flashes the P0300 for a few seconds, then corrects itself. Other than that, no codes. Idle RPMs drop suddenly to 200, but then they come right back up. Fuel trims while it does this +12 to +13% and air is about 9 g/s. I have been throwing parts at it for months now and each one seems to fix it for a while, but then the misfire comes back.

New parts (previous owner):
Plugs/wires
Cam shaft
Head gaskets
New parts (by me):
Fuel injector cleaner
Cat converters
O2 sensors
Crank relearn
Fuel pump
Coils
ECM flash

It has been at a mechanic for over 5 weeks now and they couldn't figure it out. Only thing they could tell me is that it's mechanically sound and it's only affecting one bank. Best we can figure is a new ECM? Even though it just got flashed?

Please help! I'm so frustrated with this thing, and it's camping season! Any suggestions would be so appreciated.