Why does my s-10 smell like gas after I shut it off?

it sounds like you might have a leak somewhere, check the tank and work your way to the engine bay,

4 or 6 cylinder?

4

Smells strongest near the cap. Can't smell anything in the engine compartment or the cab.

did you have any work done recently ?

Just an oil change at Fletcher's Tire.. Crawled under to look around, no signs of a leak down the gas tank or the lines. smell sure seems strongest around the fill area. But I don't see any signs of a leak around the neck. That's why I replaced the cap 1st. Could it be something with the vapor recovery system?

They're common for filler neck issues too.