It's the crazy fuel gage!
 

Hey! I know this has been addressed a few weeks ago, but im not sure where to find the answer. We have done a complete tune up, plugs wires, o2 sensors, fuel filter,
pvc to be put in tonight. We just passed emmissions-yeh :D . But the fuel gauge is going back and forth, it doesnt always stabilize after driving. What could it be? Thanks for all the help.

http://www.bonnevilleclub.com/forum/...ic.php?t=16486
check that post out, same problem I'm thinking.

I have a similar issue going on with my 99 SE too. Here you go:

http://www.bonnevilleclub.com/forum/...093&highlight=