having issue with gas gauge as well on '01 double cab, sometimes it rises when truck warms up, and it seems as if it's never reading properly except after fill up...problem is coming and going. any help or suggestions would be appreciated.

Have you ruled out something as simple as parking on an incline? Just a few degrees can change the reading significantly. If the problem is real, the culprit is almost definately the sending unit--not a big deal.

Im having gas guage problems with a 99 tacoma.
if i have a full tank and switch on my fog lights
it drops to a 1/2 tank.