Deceleration Noise
 

Hopefully someone can tell me what this means, and hopefully it's not something serious. :(
During deceleration there's a whistling sort of sound coming from what seems to be the driver's side in the engine bay.
I'm not sure if it's my exhaust bank on that side or not.
I haven't had the chance to put the car on some stands yet to get a good look, so I'm just going by ear at this point.

The sound is similar to the old style exhaust that VW Bugs had...you know those 2 straight pipes coming from the back.
Except the sound came while the VW was accelerating....kind of a high pitch sound.

The sound goes away the second I step on the gas pedal...even with the slightest pressure on the pedal, the sound will go away.

Any thoughts?
Head bolt snapped?
Exhaust gasket?

Thanks in Advance!

maybe do a compression / leak down and go from there?