Greetings, I recently noticed that my '02 SSEi'* fuel gauge doesn't give accurate readings. A majority of the time, the needle sits pegged at full. If I put the car in Park and sit with the key on for a short while (around 30 seconds), the gauge will sometimes return to the actual fuel level. Could this possibly be the sending unit?

Yes, it sounds like the fuel sending unit. If the problem is just starting, you can try a can of GM'* fuel system cleaner, as listed in this TSB
If not, you can try this.
http://www.bonnevilleclub.com/forum/...ic.php?t=71718

I had the same problem on my 2000 SE.... Bought the harness kit and installed the new float arm last Saturday(10/6/07) in fact. All better! Thanks to all for the info......
No matter now! Daughter wrecked SE on Monday. Utility trailer came loose from truck as she met him.. Trailer hit her pretty much head on..... Total lossSE! Only had 70K.......
Daughter came through without a scratch thanks to the Good Lord and GM safety...... All performed as designed!