I have a 2001 chevy monte carlo ss w/ the 3.8L engine and 128000 miles. It has a severe loss of acceleration problem. Codes that flash up are; Random cyl. Missfire (#2 & 6), Evaporative emission control. I have changed plugs & wires. I have had the injectors tested and cleaned. I have also noticed a melted sport above EgR tube in upper intake plenum. I changed the plastic plenum and gaskets along with the EgR valve. The old plenum was melted and distorted. Car still won't accelerate with any power and RPM doesn't want to get over 3000. Any clues as to the problem?
I had the same problem with my SS. Bad news for you is your mileage. I had 56,000 when it happened to me. Warranty on this fix runs out at 70,000. Cha-ching! I bet if you run it hard at night the manifolds and upper exhaust pipes glow. That's why you're torching all the plastic and gaskets.