× 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 January 2021

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
2015 Ford Transit-350 XL 3.7L MIL Lamp on VIN: 1FBZX2CM3F
P0420: Car Eff Bank 1. ... engine light. Had codes p0148 Fuel delivery error,p0174&p0171 lean both banks,po420 cat eff bank 1. Found air filter to be wet and apart. coated mass air sensor in paper. Clean air box, snorkel, and mass air & cleared codes. Back with lean and ...
January 11, 2021
2007 Kia Sportage LX 2.7L Battery light on. VIN: KNDJE72367
This is a strange one. Symptoms are intermittent but often. Charge light on, yet charging system voltage is good @ 14.4 volts. Sometimes the charge light is out and engine runs normally. Sometimes charge light is on and engine runs normally. Other times en...
January 25, 2021
2015 Jeep Grand Cherokee Limited 3.6L MIL Lamp on VIN: 1C4RJFBG2F
P0420: cat efficiency bank 1. greetings to all customer went to dealer for check engine light on.Dealer pulled coodes and does diagnostics for code po420 cat efficiency bank1 and p20096 down stream fuel trim lean bank 1 tell her bad cat and o2 sensors.Customer comes to me for repairs w...
January 26, 2021