Is my DMF knackered?

[richy klark]

I am wondering whether my DMF is broken and causing the loud clunk at the end of this video? If not does anyone else have an idea of what is causing the noise. My Ford garage has not been able to identify the fault and even at one point suggested it was the EGR valve?Video of suspect noise.

[pragmatix]

DMFs tend to rattle when on the way out,not clunk like that, 

[TomsFocus]

The engine is off for several seconds before that clunk right?  Its not DMF in that case, the DMF stops as soon as the engine does, might get a little shudder from it but that'll be pretty much instant.

EGR will be self testing at that time but I can't see it being able to make that sort of noise.

Not really sure what could make that noise though!