2002 Tahoe gas leak on top of tank

Did you replace the seal on the fuel pump?

Fuel tanks have a vent tube and a charcoal cannister to capture the gas fumes from the tank. It's possible there is a cracked or loose hose, faulty fuel cap, bad canister or a fuel leak and any one of many connections. Investigate for sign of raw fuel along the underside of te vehicle, and in the engine compartment. Attempt to follow the smell to isolate the location of a leak.

Hey man unless your vehicle is still under factory warranty probably not you can check to see if there are any recalls for your vehicle that is probably your best bet.

Its all connected.
The computer uses a solenoid to vent the fumes from the tank when the engine is running.
The vapor canister holds the fumes until the vent valve is opened.
The computer tried to vent the tank and something went wrong.
It could be from the excessive heat or something with the venting system.
A mechanic would test the venting system.

there are gasoline vent tubes running on top the tank to the filler neck. check to see if the hoses are compromised in any way. these tubes also run to the front to a evap canister check these as well.

If it is fuel injected, I would inspect the injection system. I had an injector that was leaking an puddling gas on the valve cover area. If not that, then generally check around for a leak in the fuel system / tank.

If you have ANY DAMP SURFACE AT ALL on that Tank You DO Have a Leak and it Must be Found,
The Steal Fuel Lines around the tank Get Rusty and Leak You must ELIMINATE Any POSSIBLE Leak, as this can Turn into A Tragidy.

don't over fill the tank, when it clicks off thats it!! any check engine light? I had fuel smell, and the O-Ring was leaking when I changed the fuel pump. Top of the fuel tank, was leaking only on a full tank, Also evap, pump and hoses do crack and leak but it will show, in a check engine light usually

This should be repairable from the top.
Pull out the rear seat cushion and remove the two black round access covers to access the fuel pump covers. The seals for these covers tend to leak and if they are leaking, you will see it when the covers are off.