I just got my magnapack catback installed two night ago. I noticed when I left the place that when I went over a dip in the road, that caused my car to bounce a bit, it made this popping sound from the back of my car, like something smacking metal. I ignored it, but this morning it is still persisting. I know it had something to do with the catback install. I crawled last night under my car and made sure all of the bolts were tightened, and looked for any signs of it hitting anything, but I cant see any problems. Its starting to worry me now. Any suggestions what would be causing this? It doesnt make noise if I go over a bump, but if the road has a dip in it then you can hear the popping / banging.