Finally, I got my 8 back with a new cat and that was the problem. Runs great now.

The lesson learned here is that the old coils were giving me bad ignition, which in turn was putting unburned gas into the converter. Cat burnes out over time, blockage in the exhaust path.

This all happened so slow that the ECU compensated for the idle until I needed a new battery and it was reset (hence the sudden bad idle). I never noticed the drop in power either. Bet I just gained another 5hp back... nice.

 

huh crazy **** i put my exhaust on and idles better lol