2000 5.3 hppIII, powerstat, k&n, maf descreened, tb bypass, flowmasters, taylor wires, ngk tr55 spark plugs, I am getting alot of knock retard i gapped my plugs at .050 chevy says .060 could that be a reason. a guy said i am getting knock because my truck is a ext cab and is to heavy?? if i buy ls1edit could i put more gas in there and fix it??

sure appreciate your input. (thanx)

 

Are you using 91-93 octane?

LS1 Edit can fix the problem but I would like to know what is causing it first. A heavy vehicle will be more prone to detonation than a lighter vehicle. Opening up the exhuast also helps. I would take out the HPP3 Power Tuning and see what happens. Some people get bad knock when the Power Tuning is installed.

 

I reduced the octane level from 93 to 87 on my hppIII and i did not see any Knock. but i also noticed the truck got a turtle effect (slow).

 

Then we know it is the HPP3 cuasing the problem. What brand gas do you run? Adn do you use the same gas station ALL the time?