P0420 code

PALERO

MEMBER
2002 HONDA CRV
4 CYL
4WD
AUTOMATIC
109,000 MILES

What sensor do I have to replace with p0420 code my car

Wednesday, February 16th, 2011 AT 12:19 AM

5 Replies

RASMATAZ

MECHANIC
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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Wednesday, February 16th, 2011 AT 12:27 AM

JOEY LITTLE

MEMBER
1 POST
1999 HONDA CRV
4 CYL
AWD
AUTOMATIC
150,000 MILES

I have a code p0420 that says catalyst efficiency below threshold(bank 1). What is this?

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Wednesday, February 13th, 2019 AT 8:10 PM (Merged)

BLUELIGHTNIN6

MECHANIC
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!

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Wednesday, February 13th, 2019 AT 8:10 PM (Merged)

EGUZMAN72

MEMBER
1 POST
1999 HONDA CRV
4 CYL
4WD
AUTOMATIC
180,000 MILES

What does this code mean? I think it needs a regular maintenance but I am not sure.

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Wednesday, February 13th, 2019 AT 8:10 PM (Merged)

KHLOW2008

MECHANIC
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.