Hello all to each other; my Park Avenue has had a little trouble with switching the automatic last time. But I can now exclude the automatic, since it does the same without automatics (in P). So: If you step the accelerator only about 1/4, the engine behaves quite normal, but: if you press a little more, then the engine grumbles around, and it stutters up the speed. So, what can that be???? I have heard something of a clog Kat, but how ka n n am testing this, or is it at all??? The GM people in Augsburg and Munich know nothing at all! mfg mike69