vanillagorilla

iTrader: (1)

I've never had a wide band on it. So I can only go off of what the stock O2's say. With that said, no it doesn't appear to be lean.

02sierraz71_5.3

iTrader: (2)

Good god vanilla, those are clogged cats Im suprised the thing would even run like that. PM sent

Okie5.3

iTrader: (1)

i have never seen cats clogged like that...damn. have you tried using the Seafoam or even better the GM Top Engine Cleaner? too much carbon will definately cause detonation not only by getting hot and being an igniter, but it can also increase your compression causing it to ping. i was having sporadic KR mainly at PT only once at WOT, so i shoved some cleaner through it and it made a world of difference. fuel trims went from being +3-4 to -4-5 overnight.

vanillagorilla

iTrader: (1)

I've run the Berryman's engine cleaner through the engine and fuel system. This was only a couple weeks ago, long after my cat episode. I didn't smoke at all! All I noticed was a little better low speed response. I wonder if the seafoam is all that different now. It has the same product description and instructions. I could try it again, but who knows.

vanillagorilla

iTrader: (1)

Okay, so now I really think this is temperature related. When the truck was cold, I ran it hard and it ran flawless. Once it warms up (about 160-180*) it all goes to hell. High rpm sputter and KR showing up on the gauge.

Does any one know if there's some device I can use to actually look into the combustion chamber with, through the spark plug hole? Or is there any way to tell if I have carbon build up, short of pulling the heads?

I've been planning on putting 317 heads on it for some time now, looks like that'll be happening sooner.

Okie5.3

iTrader: (1)

the GM cleaner does a better job than the seafoam, and the seafoam does a pretty damn good job. i've never tried the berrymans through the intake, so i could say how it works.