[88911cs]

Hi Guys ,
I'd like to run this by you and see if anyone has any ideas beyond what I've surmised . I have a 88 911 with under 15,000 original miles and have owned the car since new . Shortly after buying it I installed a Borla muffler and its been on it ever since . The car has always been a little louder than I would like , but I guess as I've gotten older it bothers me more so I decided to revert to a stock muffler and ordered one through my Porsche dealer . I should add that I've always had a cat bypass on the car and decided to upgrade to a stainless M+K version to replace the mild steel one at the same time I do the muffler . After installing the muffler and new bypass ( sound was nice - a little louder than stock - just what I wanted ) I took it for a ride and noticed a strong rubbery plastic smell coming through the heating system . I had cleaned all the stickers from the outside of the muffler so didn't expect much in the way of smell beyond the first time heat cycle smells you always get with new exhaust parts . After about 6-7 miles the car started to stutter and loose power and I wondered if I'd make it back to my shop . I stopped at home and did a quick check around with nothing obviously wrong with a cursory check . After a half hour I drove back to my shop and barely made it back . I checked the muffler over before installation for any plastic plugs ( there were none ) and should add that the muffler was handed to me without any packaging at the dealer . I thought it through and surmised that either the muffler had something plastic lodged from view inside or perhaps packing peanuts . After letting the car cool down I re-installed the Borla muffler and took it out for a ride - everything was fine . Has anyone ever heard of something like this happening ? The dealer has ordered another muffler which I'll see next week . Thanks for the input in advance .