Hey There, Recently I have noticed some hard shifting problems on my 1999 Buick Regal GS/Supercharged. Last week I had the transmission flushed and a new filter installed and this seemed to correct the hard shifting until recently. Now when I leave from a stop sign the car will buck and rev to almost 4grand when trying to shift from 2nd to 3rd and then shift hard into 4th, puting it into Perf. Mode only makes the problem a little better. As a test I shifted it manually and no hard shifts or high revs were happening, also I hooked the car up to a tester and it noted no codes but a shift error between 2-3rd and 3-4th according to the computer the 2-3rd shift was the worse. Does anyone have any idea what this might be, any comments would be very helpful-
Thankyou
Danny--