I've had this problem for a while now.

I noticed when I hit a bump, there is a sqeak noise like sound exactly like an old mattress spring.

It happened shortly after I placed in my U-Bend Delete so I narrowed it down to the exhaust. I though it was my resonator cover and had it removed (the cover). No luck. When I move an exhaust tip around there is no noise. It only occurs when I hit a bump.

Could it be the suspension? Never had suspension problems on my cars before so I can't tell.

Got 110k with stock suspension and exhaust.