#DIY I was correct, the fuel filler hose was blown. Got the bed up, cleaned the top of the tank off, was filthy. Pulled the old hose, clamped on the new. Bed down, got the nozzle receptacle into place and bolted on, tightened that clamp. Bed bolts back in. Ran scan, came back clear. Done in 2 hours. Drove truck around, stopped to get a copy of the key. Check engine came on during drive home. Ran scan, same code as before. Checked gas cap, wasn't seated. Cleared code, see what happens tomorrow.