Sup ht am having an issue wit my gas gauge, i left my car by a shop to get some work done and they started taking parts off my car and replacing them with their piece of **** parts so now im stuck trying to get my **** right

sooooo now my guage is not reading, i think if i fill it up it read like 1/2 tank and keeps fluctuating and reads empty most of the time, i want to know if could be the cluster or the float in the tank

car is a 00 si

 

What kind of work did this shop do? Was it electrical? Or outside, underneath the car?
More info..

Could just be the sending unit **** the bed.

 

well they didn't do anything but swap out parts, i left it there so they could tune it