hmf question

[klutchbuster250]

iv had my hmf for like 4 months and at times it sounds kinda ratlly like if theres coins in it but not always wut can it be?

[m.h.s.c.#527]

r u sure its the pipe if so it might be the header and the muffler arent connected well

[klutchbuster250]

im positive cuase if not il have an exhaust leak and i check all that when i installed it