sonic 2015LT, starts rough after I add gas , its been doing that for a while , but only recently did I get the code p0442 , and now it struggles a bit to get speed and has a rough idle.in the case I need a purge valve or hose , will that be covered under emissions or CA PZEV emissions warranty? I can see it on the list But I just want to make sure b4 I take it to the dealer and they charge me $200+