bcredliner,
no codes.....no miss....no hard starting.....
Engine goes to closed loop (throttle body behavior) after a few minutes....you can tell this due to exhaust becomes quieter at the same RPM.
I'm very sure the coils are still alright but due to resistance they tend to loose their efficiency.
I can't tell if the DME is compensating for higher ohmic values to deliver the same ignition spark values though....
Might need to compare/probe new coils vs old coils resistance.