You could have a gasoline leak.
Jeff
Or a bad O2 sensor. Get the computer scanned for codes.
Al
Tell us where you smell the gas. In the cabin? Under the hood? near the tailpipe? Where the truck was parked after you move it?
While the vehicle is idling you can get a very strong exhaust fumes odor around and in the vehicle. Fumes are are more of raw un burnt fuel. There are no visible signs of any fuel leakage. The exhast while idling spits a lot soot onto the ground.
Check your oil. If there is fuel in your oil, you shouldn't run your vehicle until the oil is changed. Fuel in oil will ruin the engine.
Jeff
The fuel pressure regulator could be bad allowing too high a pressure which lets the injectors pump in way too much gas. A relatively easy repair if that's the problem. I'd get it checked.
Along the same lines, the fuel pressure regulator could have a ruptured diaphram, and is hosing fuel into the manifold, pull the vacuum hose of it, if you've got fuel, you need a new one...
SteveL
Found the problem. Turned out to be a bad Mass Air Flow Sensor.
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