P CODES (POWERTRAIN) P0400 - P0499 P0420 Questions

On Code Po420 Cat.converter,does That Mean You Need To Replace Your Converter? Or Could Something Eles Be Wrong, I Hate To Spend Money On A...

Po420 Catalyst System Efficenay Bewow Threshow

Auxilliary Emission Controls Po420, P0430

I Got The Error Code P0420, Catalyst System Efficiency Below Threshold Bank1. I Know That I Have A Possible Exhaust System Leak, But Also...

I Initially Had The P0430 Popping, Which, Upon Checking Said My Bank 2 Catalyst Is Performing Below The Threshold. The First Step I Have...

The Upstream Sensor Is Steady, And The Downstream Is Fluctuating. Is That Considered A Bad Catalytic Converter?

Good Evening And Thank You In Advance. Recently My Check Engine Light Came On. I Checked It With A Reader And It Showed A P0420 Code. I...

I'm Getting A P0420 Code And Trying To See If Replacing The Sensor Helps.

Well I Have Been Having Problems With Knock Sensors. On Both Bank 1 And 2 And Now I Got A Code Saying P0420. And I Have Headers And A Cold...

Engine Light On, Parts Store Scan Showed P0420, Cat.system Efficiency Below Threshold Bank One. Please Enlighten Me. The Car Runs Good And...