Go5.3tt06

iTrader: (1)

My cousin called me and told me that his 2005 chevy 2500hd 4x4 6.0 engine. It was missfiring we went to autozone to scan. It say miss firing. So I got new acdelco spark plugs set of 8. I did disconnect the battery while I replaced all spark plugs. And done then reconnect. Crank up engine light went gone. 3 days later until now. He told me the engine went back on. He went to autozone to scan. Say same thing. You have idea what cause? Even new spark plugs. Impossible. Let me know quick.

Atomic

iTrader: (42)

so the spark plugs fixed it for a while and it came back? are the plugs fouled? plug wires?

Go5.3tt06

iTrader: (1)

The old spark plugs were missfiring which 5tnhe engine check showed. So I replaced to acdelco spark plugs put on. The light went away. Abut 3 days later the light came back. Went to auto zone to scan to check. It says miss firing. We have no idea why this is cause? Since the spark plugs are all brand new. But the spark wiring we reuse. This truck is only 80,000 mileage on it.

TIM Z

iTrader: (12)

If you could get ahold of EFI live or HPT , or a TECH 2 You could see which cylinder (s) are causing misfire.

Go5.3tt06

iTrader: (1)

The old spark plugs were missfiring which 5tnhe engine check showed. So I replaced to acdelco spark plugs put on. The light went away. Abut 3 days later the light came back. Went to auto zone to scan to check. It says miss firing. We have no idea why this is cause? Since the spark plugs are all brand new. But the spark wiring we reuse. This truck is only 80,000 mileage on it.

da_vato

Since there is so many miles on the engine pull the injector rails and see if there is any gunk in there.