geckvette

I had a rough idle on my 03 C5. My corvette mechanic of 15 years said I had a bad #4 plug wire. We replaced all 8 wires with the 8.5 GM wires with the heat boots. It was fine for 200-300 mile and the rough idle came back. We went back and changed the #4 spark plug. worked great for 200 miles, rough idle cam e back again. Took it into the dealership and they said 1200-1300 RPMs, number 6+7 were misfiring, then under load 3500-4000RPMs, ALL THE PLUGS WERE MISFIRING, W T F ???

The dealer is looking at it as we speak, there gonna reflash the brain, then Im gonna go reflash my mechanics brain!!

Any thoughts?........