My exhaust resonates pronouncly when decellerating at 2500rpm. The rattle i beleive would just be the exhaust hitting the heat shield, corrrect me if im wrong but i assume it is because there wasn't much clearance.

Is it resonating more at night when it is cooler? I notice during the warmer weather that it doesnt do it soo much. It is also more pronounced with the aircon on.

Anyway, i learnt to live with it. I just have a catback thats 3inch if thats helps.