p0420 code

2003 DODGE CARAVAN
100,000 MILES
Avatar
CCI
  • MEMBER
  • 6 POSTS
My van's check engine light is on. I got the code read and it shows a p0420. I checked the book and it says it is Catalyst System Efficiency Below Threshold (Bank 1). The van idles fine, when I go up hills (in Colorado) it feels like it lacks power. Do you think it is an O2 sensor, or is it the catalytic converter? What is a way that a layman like myself can tell?
Thanks
Apr 12, 2013 at 11:22 PM
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.
Advertisement
Avatar
CARADIODOC
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 34,308 POSTS
The code means the oxygen sensor after the catalytic converter is reading nearly the same as the one in front. That means no change is taking place in the composition of the exhaust gas as it passes through it. The catalytic converter is not doing its job. The oxygen sensor is working properly because it reported the condition to the Engine Computer.
Apr 13, 2013 at 12:20 AM
Advertisement