Hi I have a question, on my way home today while I was driving I heard some boiling sound (like hot water in a closed pot). So when I got home I check my rear and the sound was coming from my hks hi power exhaust. Did something put something inside my exhaust? And I also heard some squeaky sound from the back (not the rotors/brakes), but it was coming from the rear also(might have something to do with the exhaust)

Sorry if not in the right section