Been doing some reading on this. Either a very simple gas cap, or hair pulling.

What has your experience been?

Mine is a 5.4. Cleared the codes with a reader, tightened the gas cap, waiting to see if the light comes back on.

 

That would be the first thing I would do...


- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- Evaporative Emission (EVAP) canister or fuel tank leaks
- Evaporative Emission (EVAP) system hose leaking
- Fuel tank leaking

Read more: http://www.engine-codes.com/p0456_fo...#ixzz49gchvkO8

 

I've had it before and it ended up being nothing, so I'm assuming it was the gas cap? I made sure the gas cap was on all the way and the CEL disappeared after a few miles.