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Discussion Starter · #1 ·
I installed my lt, e fans, and tuned Pcm couple weeks ago. Ever since it has run like crap. Super rich. Like make your eyes water rich. It drives awful no real power it runs rough and feels like it's going to die at stop lights. I replaced new plugs, new wires, ran good for about 2 days now it's still running rich. Checked no codes, none pending. Tuesday on the way home cel came on. Knock sensor 1&2 codes. I'm at 190k is it really the knock sensors bad or is something else tripping them. If I drive it hard all you hear is back fire in the exhaust. I'm kind of lost.

Thanks for the help
 

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Discussion Starter · #3 ·
Vengeance racing. It's only a mail order tune.
 

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Im gunna say its in the tune. I would call them up and see if they have a scan cable where you can make some logs to sendvto them or a autocal or somthing of that nature.. that would be my first guess
 

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Discussion Starter · #5 ·
Before I blamed the tune I wanted to double check a few things. i came across a few problems. One I went by the underhood gap specs and gapped to .060 and now gm says to do .040. I changed to brand new plugs again and double checked the .040. Then while doing that I noticed one plug wire was laying on the header. Wrapped it and seems fine now. While doing that I noticed the plug for my knock sensors wasn't even plugged in. I have no idea how that happened. I drove around for a little bit and the light went out and the truck seems like a whole new beast. Hopefully that solved the problem.
 

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yea there is that. I was saying the tune based on the fact that everything was done correctly esp. The knock sensors will cause them to run like crap.
 

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Discussion Starter · #7 ·
Yeah. I'm still not sure how the harness got unplugged. Drove it yesterday and today still running good.
 
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