P CODES (POWERTRAIN) P0400 - P0499 P0420

Passed My Smog Test, And Soon After The P0420 Displayed, Took It To Dealership And They Said There Is No Problem With Cat Converter And...

I Have An 03' Cadillac Deville Base Sedan And It Is Throwing The Code P0420 (catalyst System Low Efficiency Bank 1). This Code Just Came Up...

Car Was Throwing Knock Sensor Codes P0325 And P0330. Check Engine Light On. Car Radio Intermittently Goes Off Then Comes Back On And When...

So, For The Past 4 Months In New England, It’s Obviously Winter And Anytime I Start My Car In The Morning And It’s Below 40 While It...

2006 Grand Caravan 3.8l, 72,000miles. Has A P0420 Code, Catalyst Efficency Below Threshold Bank 1. Would That Be A Up Stream 02 Sensor? I...

Vehicle Is Throwing P0420, Catalytic Converter Was Replaced Last Year (but Son Drove It Around Campus For Months With Code Returned). Live...

2001 Pontiac Grand Am 3.4l V6 P0420 Catalytic Efficiency Bank 1 Code Was Tripping Every 15 Miles. After Replacing The Thermostat Which...

Hello, I Have A 2000 Camry With 4 Cyl Engine And Ca Emissions. The Car Overheated Due To Broken Water Pump, And I Replaced The Cylinder...

Got The 0420 Code, O2 Sensors Checked Out Okay, Both On Obdii And With An Ohm Meter. Less Than 50 Degrees Temperature Difference Between...

I Have A Problem With The Same Code (p0420) Coming Back. I Own A Actron Auto Scanner Model Cp9180. I Look The Code Up And I Get Catalyst...