RSX problems

[Brap_Brap]

At idle there is a buzzing/rattling noise coming from underneath my RSX and I don't know exactly where it's coming from but everytime I shift gears at 3000+ RPM I can hear the rattling get louder then it is when the car is idling. The rattling when I shift goes off kind of like a blow off valve.

Anyone know what's wrong?

[JTC180]

Exhaust leak?

[realazy]

Either exhaust leak or a heat shield is rattling.

[911fever]

heat shield maybe