P CODES (POWERTRAIN) P0400 - P0499 P0445 Questions

I Have Recently Got The Codes P0445 And P0449 Have Come Up. We Have Replaced The Evap Canister To Cover For The P0449 About 3 Weeks Ago...

Got My Oil Change Done This Sunday At Local Chevron Station For My 2001 Nissan Altima (i Put Valvoline Oil). They Told Me That Fuel Injector...

The Code Was For The Fuel Cap, And I Changed That, But After A Few Miles The Light Came Back On With The Same Code. Was Tould It Could Be A...

Check Engine Light Came On. Test At Parts Store Gave Code Of P0455. Checked Canister And Vacuum Lines - Ok. After Last Fill Up I Parked...