Something happened before this issue started from the sounds of page 4.
Please confirm that all was good before that large curb.
On my 97 SSEi, recently I was getting a lean bank continually and trying to determine what was happening. The car can dump fuel in an effort to correct a lean condition. A fuel pump, strainer and filter later...my car seems to be back up to par.
Have you checked the fuel pressure?
Last time the fuel filter was changed?
Considered that the curb might have dislodged something with the fuel system/pump?
Admittedly I haven't read the entire thread. My thoughts would be to put it up in the air and look over the tank, fuel lines and anything in the path.
00 Regal GS: All kinds of cool stuff.