Well ive been having this really annoying noise from under the passanger seat near the engine when ever the car would boost i took it to the dealer, to get the new interior pieces due to pealing and mentioned it. The mechanic said its my exhaust muffler i installed but i said no this is different its my car trust me, he said he saw nothing ok fine i took it and left. Well a week later it gets louder and now i cant take it i jack the car up and search i push my exhaust and bingo between the headers and cat, the flex pipe is cracked half way around...hm cant find anything huh well not i took it back and should be 4-5 days till the piece gets in, but i was also wondering, im pretty sure its fine but does it hurt to drive like this or should it just be fine. And guess what im guessing it is from wheel hop, and our engine mounts. Well if anyone has a weird noise when underload check the flex pipe!

 

those flex pipes crack on HHRs sometimes. i havnt seen one on a cobalt yet though. I wouldnt drive it around a whole bunch, just because it can cause a p0171 and mess up your fuel trim values