My 1998 gmc sierra's fuel guage is turning around and hitting oil pressure guage.?

[Mark]

Is it a bad sending unit or is the guage messed up

 

[Molson02536]

Is it a bad sending unit or is the guage messed up

Sound's like a bad Gauge, the Stepper motor can be replaced on the instrument panel. Do a search on EBAY for stepper motor, that go for around $15.00 and will come with instructions for you to get the job done.