troule code p0420

HONDA CIVIC
Avatar
VEVEYA
  • MEMBER
  • 1 POST
1997 honda civic 100040 mileages.
my check engine light was on. the diagnostic trouble code is P0420------ Catalyst System Efficiency Below Threshold (Bank 1) , one repair technician told me I should replace a new catalyst converter, but another one told me to replace the new O2 sensors, what should I do? thanks.
Aug 13, 2006 at 11:59 PM
Advertisement
Avatar
SERVICE WRITER
  • ✓ASE Certified Mechanic
  • 9,123 POSTS
  • ASE Certified Mechanic
Have someone check the 02 sensor wave patterns on a scope or for being out of spec. In particular the front one. Converter is probably fine,but further testing should be done. If testing was done, not just a conversation, then you'll need to have faith in one of the techs. That code points to bank1-02 sensor. The front sensor evalutes gases before entering the converter and the rear one evaluates it after the converter
Aug 14, 2006 at 10:13 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.