Here is the scoop. A few weeks ago I had the timing chain, Opti, and coil replaced on my 1995 Z28 to try and fix a miss above 5200 RPM. What was found was a plug wire that was almost all the way off the Opti and had ate away most of the terminal.

One thing I have noticed is the fuel mileage has declined by about 4-5 mpg, especially on the highway. Any ideas?

BTW: I tried a search and found nothing useful for this.