trouble code

Hi I'm new to the site I have a fairly good working truck but the check engine light is on. I checked the fault code and p0441 came up which i think is a evaporative purge flow system code. Dose any body know if this is something that has happend because of my exhaust system? what
dose it do? How bad is it? And can I fix it my self? please help.

That's not a result of your exhaust. The evap system takes fuel vapors from your fuel tank and stores them in a charcoal canister. When it's time for the engine to turn on, it purges those stored fumes in the canister into your engine to be burned. A few things that could cause your light to come on is not having the gas cap on tight, overfilling the fuel tank to where it is purging liquid fuel and not vapor or a faulty leak detection pump. Those are a few things that could be wrong.