is your 1M's inner exhaust pipes BLOCKED?
pls upload some pics or videos of your exhaust.
This is how I tested the 1M's inner exhaust pipes:
http://v.youku.com/v_show/id_XNDQyMzAxMDY4.html
This is the sound before taking the block(the original exhaust sound)：
http://v.youku.com/v_show/id_XNDQyMDcwNDg0.html
This is the sound after taking out the block(pls see the following pics):
http://v.youku.com/v_show/id_XNDQyMDcwOTY4.html