325e low flow muffler

My 325e has 230k miles and it is to quiet, i bought a $30 low resistance dtm muffler from ebay, i was just wondering if i put this on will it increase power or gas mileage? Also is it bad for the engine? Thanks

performance, no. gas mileage, no. louder, probably.

for performance you got to do both intake and exhaust, to do anything noticeable. and changing a muffler is changing exhaust, like doing a cat back or full exhaust.

Thanks, will it harm the engine in any way?

itll help the engine rev a tid bit quicker. but as long as the cat is still installed and flowing freely, no damage will be caused