Nissan Altima P Codes (Powertrain) P0400 - P0499

I Have A 2008 Nissan Altima I Kept Getting The Code P0420 Which Resulted In Me Getting Another Transmission (used) Got That Put In I Can...

I Got The Code Awhile Back And Replaced My Catalytic Converter The Manifold One And The Code Came Back Couple Hundred Miles. I Have Checked...

I Removed The Cat Converter, But There Seems To Me No Damage Visible. Please Advise

About A Year Ago In My Car, The Engine Light Appeared. I Used A Scanner To Try And Find Out The Problem, And It Returned A P0400 Code. I...

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...

I Just Recently Gotten The Code P0400 Yesterday But I Also Had The Code P0171 For Like A Week, I Have Been Searching Up Ways To Fix This And...