× Auto Repair Pros Member Benefits TechHelp Knowledge Base Forums Resources My iATN Marketplace Chat Pricing About Us Join Industry Sponsors Video Members Only Repair Shops Auto Pro Careers Auto Pro Reviews
Join Now
International Automotive Technicians Network

P0420 Diagnostic Trouble Code Discussion for October 2006

Catalyst Efficiency Below Normal (Bank 1)

Note: This is a professional automotive technician's resource.
Vehicle Owners: If you are seeking an automotive repair professional to service your vehicle, visit the iATN Repair Shop Finder.

Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2000 Chrysler Sebring LXi 2.5L MIL Lamp on VIN: 4C3AU52NXY
P0420: left bank catalytic converter efficiency failure. chrysler guru, i have a customer who recently had his rear cat. change (between flex pipe assembly & exhaust pipe)from a exhaust shop that guaranteed him he would pass emission,not! well anyway i am trying to help him out,without second guessing which co...
October 01, 2006
1997 Mazda Protege DX 1.5L MIL Lamp on VIN: JM1BC1412V
P0420: Catalyst Efficiency Below Normal (Bank 1). when this vehicle first came in code p0420 came up. at that time it was noticed that the manifold was cracked. this was replaced and customer took vehicle home. next time in (300 miles later) p0420 came up. the rear catalytic converter was checked and determin...
October 06, 2006
2000 Honda Odyssey EX 3.5L MIL Lamp on VIN: 2HKRL1864Y
P0420: Catalyst Efficiency Below Threshold (Bank 1). Hello all and thanks for your time. I have checked this van out twice. Both times the owner said the light just came on and didn't notice any problems with the performance. Both times I did the tests as per the flow charts and come to the conclusion that the p...
October 16, 2006
2000 Subaru Outback 2.5L MIL Lamp on VIN: 4S3BH6751Y
P0420: Catalyst Efficiency Below Normal (Bank 1). I'm posting for another tech who has this subaru that initially had a cat efficiency code. He replaced the front af sensor, and then drove it. A new code returned which indicated the circuit malfunction. We checked the wiring and connections from the pcm to th...
October 30, 2006