nah dont think its a relay, its the sensor itself, the float (arm) or the gauge. Stepper motors are what they call the little motor that turns the gauge arm.When you say "Step" is that a piece on the fuel pump that look like a Bicycle pedal hanging on the side? And is i got a Relay tucked underneath and close to the back bumper, Think that could be the problem? And thank`s the both of you for the 411
???Did you change the sensor too? Was it on the new pump? If not you will probably need to change the level sensor.
in the 2000s the step motors that move the gauge went bad alot in GMs also. They are a little bit hard to change but if you have a new sensor and it still reads wrong then the gauge motor may be bad.