[horsepower_and_hounds]

So instead of starting a new thread for this question I will tack onto the OP because it is similar.

I installed the MPE and when at start up the flap is closed the exhaust is very loud. At 5am in the morning in the garage on a work day it really resonates. I was thinking about doing the mod so it is open all the time and it would be quieter at start up but not sure what the negative effects would be and why it exactly exists in the first place. Is it to help CAT warm up and/or the get the EGT's up quicker? I would have thought when you upgrade to a M performance exhaust this would be one of the items they would do away with so I figured there was a legitimate reason.

Sorry for all the wind.....thanks