[200q20v] Off-throttle kick

[Joe Vanzeipel]

Greetings listers,

I replaced the turbo bypass valve a while ago in my 200q20v. Replacing the
worn valve stopped my stalling problem, and now my car makes the cool
"swoosh" sound when shifting. However, my car still has a "kick" when I get
off the throttle after cruising. If I were to hold the tach at 3k and
suddenly let off the accelerator (but not pressing in the clutch to shift),
the car will kick or buck. A simular thing happens when I mash the throttle
at low revs. The symptom is easily noticed in all the gears, with 1st being
the most and 5th being the least.
I think this is a vacuum leak, but I am not sure. Has anyone have a BTDT on
this kind of thing before? Is there a very simple thing to do to check a
vacuum leak? I tried the dipstick pull out method described on SJM's site
and I didn't notice a change.

Thanks,
Joseph (200q20v "Vanessa" @ 112k)