At first I thought a loose heat shield but I noticed it gets worse once warmed up so now I suspect a loose cat element.
Second opinions?

[media]https://www.youtube.com/watch?v=tyqOqUuF7kI&feature=youtube_gdata_player[/media]

 

I have a similar noise, I thought it might be a heat shield, it also comes through the transmission tunnel when the car is on the over run.

 

I had exactly this three weeks ago, it was the cat! I bought a Berk High Flow cat for around £240, sorted! Don't even look at the Honda prices.

 

If it is my CAT, id probably but a decat for the price of a CAT, and then just bolt it back on for MOT time.

 

https://www.s2ki.com/s2000/topic/102...#entry22619036

Sound like mine? Checked the cat and it looks fine visually. Then checked my old MOT and it has an advisory for a missing heat shield bolt so now i'm figuring it's the heatshield!

 

Naturally this is the first check, but sadly mine was ok. Once removed, it was clear to see that the cone had come loose inside, it was moving back and forward and inch or so.