P CODES (POWERTRAIN) P0400 - P0499 P0420

Engine Light Came On. We Get Two Codes, Both Showing P0420. Since This Code Came Up Twice, Does This Mean That The Catalytic Converter...

I Have Got This Code 3 Times In The Last 4 Months Is There Anything I Can Do? I'm A Fairly Good Mechanic. The Code Is P0420 Catalytic...

I Have A 2001 Toyota Camry With 170,600 Miles Has P0420 Code That Came On Twice. What Could Be The Problem And What Needs To Be Replaced?

How Do I Correct My 2000 Toyota Camry Ce P0420 Code?

I Recently Had The Po 420 Code Show Up On My Grand Marquis. I've Replaced The Downstream O2 Sensor On Bank One. It Didn't Fix The Problem...

I Have A P0420 Odbii Error Code P0420 Means "catalyst System Efficiency Below Threshold (bank 1)" I Have Done The Following. 1...

Can Fuel Trims Affect The Efficiency Of The Catalyst. Long Term Is Around +13 Short Term Is Around +6. I Had A P0420 And Went Away.

2003 Chevy Impala 6 Cyl Automatic 90,000 Miles I Would Appreciate Any Help Or Advice. The Check Engine Light Just Came On In My Impala...

I Had Random Misfire Code But I Fixed It By Replacing A Faulty Coil. I Have No Miss, But I Now Have A Po420 Code. Replaced Up And Down...

My Check Engine Light Came On With The Code Of Po420. Yesterday I Got The Flex Pipe, Extension Pipe, Resonator, Axle Pipe, Muffler And...