Gas gauge reads full all the time, and can’t get more than a couple of gallons of gas to go in without gushing out of the gas cap. Any ideas?
Either you have a big dent in the gas tank that’s pushing up the gauge sensor or you have a short circuit in the wiring from that sensor to the gauge.
Or a bad sender in the tank or a bad gauge.
Regarding the can’t get more than a coupe of gallons in comment, do you mean you have to repeatedly stop filling, then start filling, or that even if you drive enough to need say 5 gallons, only 2 can go in?
How many miles have you driven it before attempting to fuel it ?
Maybe your gauge works just fine and you’re fueling to soon.
^ This. If you can only squeeze a couple of gallons in, it’s likely your tank is nearly full and it’s not surprising that the gauge reads full.
Unrelated to fuel gauge, but that symptom can indicate a problem in the evaporative emissions system. Faulty canister or purge valve for example.