My check engine light has been on for a couple of months. I previously checked the code and it was a po442 (medium evap leak) and a changed the gas cap but that didn't help. I let it go and happened to check the code again yesterday and now it is a po455 (large evap leak). Two questions 1) Is it something to be concerned about or can I let it go? 2) Where is the charcoal canister so I can check the hoses? It is a 2002 quad cab 4wd 4.7 5spd. Oh, also my exhaust smells nasty so I assume it is the cat. Also I went under the truck and the cat was supper hot compared to the rest of the exhaust. Is there a aftermarket cat I can get that will increase flow and not cost a ton. I have a flowmaster super 40 on the truck and I don't want to make it any quieter if anything I want it louder (if the can has any effect on noise). Thanks

 

evap leak will give you really crappy fuel milage, the charcoal canister should be right infront of the fuel tank, check for dry rot or and burn marks on the lies or any chafing, also look up in the engine compartment, and with the cat, put a high flow cat in place, look at a bunch of exhaust companies, others should chime in with the brands they prefer

 

remove the cat all together if you can. If you don't have road tests for that