2005 RB FF182
Bought a brand new scorpion exhaust and decat. It's been fitted for around two months now. every time I hit exactly 2500 rpm I hear a slight rattle. If u just sit and rev the car you cant hear it. The exhaust is clear of all heat shields axle etc. No clamps are loose. Even fitted a new genuine cat fitting kit and gasket. Still no luck. Can any help or suggest anything. Thanks