NISSAN P CODES (POWERTRAIN)

I Have This Code For A Af Sensor I Have Already Replaced It However Code Is Still Their.

Had Fault Codes That Say The Egr Valve Is Faulty, So I Replaced This With Another One It Wasn’t Genuine So Maybe That Is Faulty As Well...

I Look Up These Codes And They Are System Too Lean On Bank 1 And Bank 2. What Do I Do To Fix These?

Throttle Control Motor Relay? Location Of The Relay And The Estimate Cost Of The Problem Caused?

These 2 Codes Are Still Coming Up Even After The Top 2 Sensors(still 2 Below Manifold)have Been Replaced, By Reading The Definitions Of The...

Replaced Plugs, Wires, Cap, Rotor, Injector, Comp Test, And Checked 4 Vac. Leaks Still Misses In 2k Rpm Range Only

Hello I've Got A 2001 Nissan Altima With How Do I Go About Finding The Problem And Rectifying It? I've Changed The Intake Gasket...

Engine Light Came On Took To Dealer Said It Was Rear Catalytic Converter And Now Engine Is Back On And They Said It Might Be The Front One...

I Havn't Really Tried Nothing Because It Is Dark Right Now I Doubt Its Gas Cap Its Still Factory Cap.

Does This Mean The O2 Sensor Is Not Working?