p0420 code

2002 HONDA CRV
109,000 MILES • 4 CYL • 4WD • AUTOMATIC
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PALERO
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  • 3 POSTS
what sensor do I have to replace with p0420 code my car
Feb 16, 2011 at 12:19 AM
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.
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RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
Hello,

This code Catalyst System Efficiency Below Threshold (Bank 1) is because the catalytic converter is worn out here is a guide to help walk you through the replacement with diagrams below to help you with your car.

https://www.2carpros.com/articles/catalytic-converter-replacement

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.
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Feb 16, 2011 at 12:27 AM
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JOEY LITTLE
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i have a code p0420 that says catalyst efficiency below threshold(bank 1). what is this?
Feb 13, 2019 at 8:10 PM (Merged)
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BLUELIGHTNIN6
  • CAR REPAIR CONTRIBUTOR
  • 16,542 POSTS
Usually a faulty O2 sensor will throw this code. Need to check your oxygen sensors. Follow the link below to learn how to test an oxygen sensor.

https://www.2carpros.com/how_to/how_to_test_oxygen_sensor.htm

If sensors are OK, need to flow test the catalytic converter..

Thanks for using 2CarPros.com!
Feb 13, 2019 at 8:10 PM (Merged)
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EGUZMAN72
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  • 1 POST
what does this code mean? I think it needs a regular maintenance but i am not sure.
Feb 13, 2019 at 8:10 PM (Merged)
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KHLOW2008
  • CAR REPAIR CONTRIBUTOR
  • 41,814 POSTS
Hi eguzman72,

P0420 = Catalyst efficiency below threshhold.

Usually this means the catalytic converter is bad. It is not a regular maintenance item.
Feb 13, 2019 at 8:10 PM (Merged)