I recently replaced my stock wires and plugs with MSD 8.5 mm superconductors and TR55's gapped to 0.060.
My car is a 99 WS6 with ~ 131K miles and basic bolt-on's installed.
The car is rarely driven and it ran ok before the plug/wire change.
It took me a couple of evenings to change all of the plugs and wires and the whole time the car sat with the battery unhooked. I did unbolt and shift the passenger side coil rail up to allow more access to #8.
Finished the job, hooked up the battery, started the car up and it began idling rough and hesistating like a miss. Checked all of the plug wire connections and all felt tight.
Test drove it for a few blocks and the problem didn't clear up so I put her back in the garage
Took the car into a mechanic friend of mine the next day who installed an ORY and new covette O2 sensors. He checked all of the plug wires to make sure each end was seated properly and didn't find a problem.
He hooked up a scanner and did not find a misfire.
Picked the car up and it still stumbles when I get on it. Unbelievably loud with ORY and LM1 catback!
My SES light has been on for months since I completed the EGR and AIR delete.
Any helpful advice would be greatly appreciated.