Honda Civic P Codes (Powertrain) P0400 - P0499 P0420

Browse Honda Civic P Codes (Powertrain) P0400 - P0499 P0420 questions and answers. Choose a question that matches your symptoms.

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2004 Honda Civic Po420

2004 HONDA CIVIC

Engine Performance Problem 2004 Honda Civic 4 Cyl Two Wheel Drive Automatic I Have A Civic 04 Ex What Is A Po420 Code What Is That I...

1 ANSWER

Asked by oscar4500

1998 HONDA CIVIC

My Car Is Running A P0420 Code. My Exhaust Manifold Clearly Has A Crack Between The Manifold Gasket And The 1st O2 Sensor. Is It Possible...

1 ANSWER

Asked by ajgary

1998 HONDA CIVIC

I Recently Replaced The Radiator, Hoses, Thermostat, Plugs, And Wires. Car Was Ran A Few Times With Misfiring Plug, Now I Get The Cel With...

7 ANSWERS

Asked by seatazzz

1996 HONDA CIVIC

Hi Guys, I'm New To This Forum And I Need Some Expert Advice. A Friend Of Mine Was Kind Enough To Lend Me His Ez Scan 6000 So I Can Check...

1 ANSWER

Asked by tigaperbyu6

1996 HONDA CIVIC

Engine Light Came On....ecu Code Po420 Says It Is Catalyst System Efficiency Below Theshold(bank 1). Little History: The Car Has...

1 ANSWER

Asked by BigD

HONDA CIVIC

1997 Honda Civic 100040 Mileages. My Check Engine Light Was On. The Diagnostic Trouble Code Is P0420 Catalyst System Efficiency Below...

1 ANSWER

Asked by veveya

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