: Rough Downshifting

10-05-08, 01:44 PM
I own an 05 STS with the Northstar V8. I recently had a problem where the car "bogged down" going up hills at about 35 MPH. The dealer upgraded the software which changed my shift points which has solved the bog problem. I now notice that when the transmission down shifts (especially at 40 MPH) it is very noticeable. I brought it back to the dealer who doesn't feel the problem. I feel it everyday and no doubt exists in my mind that this upgrade has broken something else. Anyone else out there have any experience with this and if so, what was the fix.