scottwizer

I am having some problems with my SS 2001 Camaro. It is a 6-speed car. Unfortunately not the first problem. The car has been a great car. It started last year when the engine had an oil consumption problem. The dealer determined that the oil consumption was due to faulty rings that are experienced with 6-speed cars. Consequently they took down the engine and replaced the rings. Since then there have been a few problems that they can't seem to answer or fix. First, recenctly it has decreased fuel mileage, I tried the normal fix of a new air filter which seemed to help but did not cure the problem. I am not sure what else to check. The mileage has gone from about 200-220 in town to 150-175 per tank. Also intermitantly the idle seems to run high. Every now and then the idle will sit around 1500-2000 rpm when sitting at a stop light after driving for a while. This happens very rarely, but I am not sure what the cause could be. Lastly, the car has a sort of backfire sound when the car is warmed up. I know it is common when it is cold, but it seems to continue even when it is warm, and only during deceleration. The only mod is a flowmaster muffler. It did not do this before the engine was taken down, even with the same muffler. Today it is at the dealership again... and they seem to have no clue and say that there is no service engine soon light, so there is no problem. The car now has 26000 miles on it. Do you guys have any suggestions on how to correct these three problems? I wanted to correct them before I install the new cat-back borla system to make sure everything is in perfect working order. Thanks for the advice.