If you haven't already tried this:
* Turn on Game
* From main menu (Arcade Mode, GT Mode, Replay Theater, etc, etc.) select OPTIONS
* Scroll down to CONTROLLERS, Click on STEERING (Top Row, 2nd from Right on the NTSC versions)
* Scroll down to bottom of list & set "Driving Force Pro Feedback strength 1P" to MILD
* Then "R.T.F.M." on how to adjust the FFB setting on the actual DFP wheel