06 MCS with automatic transmission and mono ball muffler/exhaust mod. Getting resonance when RPMs drop when shifting from D to R or just coming to a stop at lights, intersections etc. Had heat resistant silicone applied to heat shields toward motor end of exhaust piping channel and added a custom hanger for the remaining muffler for better stability and balance. Removing the custom dog bone stabilizer by the front motor mount and a brand new OEM motor mount has reduced the vibration but not eliminated it. May need to get under car and replicate noise for a muffler shop but ideas on what may be causing the noise may help if anyone has experienced the same. Prob not a big issue for cars with a clutch since you can eliminate load of the drivetrain and the resonance of the exhaust system bye imply pushing in clutch approaching a stop.

 

Well....two things are abundantly clear to me now:
1. I'm the only one on NAM who has an MCS with ST coilovers
2. I'm the only one on NAM running an automatic tranny car with with the mono ball exhaust mod.

 

Never heard of this mod ? What does it do ?

 

Just a delete of one of the mufflers and modding the plumbing for it. Less weight, more burble....and....resonance at idle- only happens under some load at low rpm. Not an issue for manual tranny cars since clutch is in or in neutral at stops with no load.