The check engine light (456) came on again recently. It actually came on and stayed on for a couple days then went out by itself and now has been lit again for a couple months.

Had it in the shop today. They went over it with a fine tooth comb (is that the expression). Everything looks good (gas cap is nice and snug). The mechanic thinks it may be time to replace the evap canister. Our's is about 17/18 years old. Is that a long time for such a part ? We also live in a part of the world with unexpected speed bumps all over the place and it is very easy to bottom out the Jeep (sometimes pretty hard).

Thanks

 

Unless the Evap canister is cracked I don't think it needs to be replaced. I think it would be a fool's errand.


P0456 is a small leak. Replace your gas cap. Just because it's nice and snug doesn't mean anything.

 

I agree with Ken. Replace the cap with a quality one (Mopar or Stant). Simple stuff first and the cap has been known to be the culprit for this code.

If that doesn't resolve the code, a "smoke test" of your evaporative emission system can be very helpful in isolating the root cause.

Here is more information on this code. Good luck!

https://www.obd-codes.com/p0456

 

Check all of the rubber hose evap connectors also. On my Cherokee, it was the one next to the frame rail under the floorboard that was cracked. It is the one between the metal line and the plastic hard line.

 

good excuse to enjoy a cohiba.
but i agree, start with the gas cap. and smoke a cohiba anyway. lol