wierd exhaust sound

[Billy Goat Burner]

I have a wierd exhaust sound thats bugging the crap out of me, It sounds like an exhaust leak at the manifold but the sound is not at the manifold, you can only hear it at the tail pipe. I have checked for leaks and there are none. when I had it straight piped it was very annoying. I have a banks SS monster exh. muffler on it to tone the beast down some. O.K laugh if you want but it sounds like pffffft pffffft pffffft pffffft any Ideas of what it may be? an ex ford mechanic told me they had a problem in a few trucks with the Y pipe where a piece of the pipe would get lodged inside causing it to act like a valve or some crap

 

[argve]

Typically this is a sign of an exhaust valve that has gone bad. Pull the valve covers and look for signs of exhaust gasses entering around the valve stems.

 

[Billy Goat Burner]

I'll take a look around in there and see,I have this sound/video can it be loaded on here for someone to hear?

 

[wgargan]

you can load it up to youtube.com or photobucket.com

and then post a link like this:

http://s236.photobucket.com/albums/ff240/wgargan/?action=view&current=MVI_0076.flv

or

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