Last night I replaced the generic and awful catback that came with my car. I just got back from my first drive with it. The Cobalt single tip is a huge improvement - no more rattles and a much improved tone, but, it smells like a burning mixture of plastic and machine oil. I'm assuming this is normal, but this is my first exhaust install. Is it normal for a new exhaust system, specifically one from Cobalt? I tried searching, but didn't find anything definitive.