Sticking accelerator on A4

[DavidH2335 <DavidH2335@aol.com>]

When pushing down on accelerator, occasionally, I am met with fairly heavy
resistance.  If I push hard, the obstruction frees and accelerator works OK.
Only happens about once a day, and it seems it wants to do it as I make 90
degree turns to the left.  Dealer can't find it and I can't make if fail while
they are using it and I'm sure it's not me (or shoes or anything visible).

A4 is Quattro and AT.

Thanks in advance.