POcode 171 fuel to lean

I'm really hoping for some advice I have replaced a catalytic converter both exhaust sensors ECU sensor and still after I drive my truck for a little while and shut it off for 5 to 10 minutes and try and crank it back up it won't turn over and I can smell gas. Then just wait another 25 minutes for the motor to cool completely down and turn the key and truck will crank rite up does anybody have any ideas. Please send a reply

 

You go down the list of trouble items for that code yet?
Could be the MAF, could be a vacuum leak, the fuel pump, etc