The rundown is, I was having some power issues after the car was dynoed and tuned. The dyno operator said I needed new valve springs because my graph was showing some wavey lines up top around 5000-6000 rpms, but down low it would pull good until 4000 rpms. Well, long story short, I was skeptical from the beginning about there advice so I diagnosed it myself, by just simply checking the spark plug gaps, they had it gapped between .20-25, first mistake, plus I was getting a popping sound from the exhaust they was driving me crazy. Anyway, I spent a lot money on this C5 to get it running right with the procharger. I was just about to give up on this car and sell it because I was so discusted with the popping noise and it was not running right and I spent all this money on it.

Well the only thing I had to change out that was original was the wires, bought MSD super conductor from amazon, took the plugs back out re-gapped to .35. And problem fixed. I can't believe the difference how strong the car is and running great. The idling is much better and consistant not up and down. I actually believe I gain about 10-20 hp, because no spark was being generated on 1 of the cylinders, because of faulty wires and to tight of a gap on the plugs. No more popping from exhaust and feels like more power. I am not surprised I was down a cylinder. Don't know why hp tuners and any scanners did not reconize and codes were set off. I believe one of the plugs were gapped to tight and were not fully igniting the fuel/air mixture. Also the wires on the inside were bent and not fully connected to the plug.

So if you are having engine trouble and don't know were else to look, it may be those wires not fully engaged or bent on the inside or the gaps on the plugs maybe too tight or to bug. Hope this helps.

 

It happens the simplest thing can get overlooked. Going back to the basic air , fuel and fire.