So i keep getting the check engine light popping up. Took it to a parts store they read the code it came up as a PO456. he recommended tightening gas cap and if light remains to replace the cap. The weird part is I was going to just buy a new gas cap to save time and trouble. He recommended I buy it directly from Dodge dealership and not from him? Is this truly necessary? Is there some special part number for the gas cap? I just want to not get the light coming on as its annoying. Thanks

 

Hell no, I have a locking cap from Autozone on mine. But it probably isn't the cap. It's an evap leak from somewhere in the system and the easiest thing to check is the gas cap. Trace your evap lines, look for a split hose or a broken hose clamp and replace where necessary. Problem is often found around the canister.

I have an evap system map in the FAQ section...