when my s2 is moving and the throttle is shut the exhaust makes a rattling noise as if there is something inside the exhaust, it stops as soon as you apply the throttle and occasionally does it when the car is ticking over stopped, it is quite loud and noticable im not sure if its just because it is straight through. any ideas?

 

check that the down pipe isnt loose or any other clamp the exausht is not catching the underbody at all is it

 

Mine duz it it's just where the exhaust is hitting the bottom of the car where its not positioned properly