Showing code P0420 for the last 4 months.

Asked by Apr 09, 2017 at 06:01 PM about the 2010 Honda Accord LX

Question type: Maintenance & Repair

Engine light was on. Showing P0420 (since 4 months). Dealership quote was
too expensive, they said catalytic converter needs replacement. Engine light
disappears/appears frequently. Don't have too much money to spend.
Please let me know how to proceed on this issue to minimize expenses. Is is
due to O2 sensors, or a choked and defective catalytic converter?

1 Answer

73,015

You should go to a independent exhaust shop if the catalytic converter needs replacement. After market cats are much cheaper than the OEM. Plus their labor rates would be lower than the dealer. The P0420 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be replaced to fix the problem. If the P0420 code is combined with other codes, try fixing the other codes first.

Your Answer

Add photo

Related Questions

Search Honda Accord Questions

Honda Accord Experts

#1 Tom Demyan
Tom Demyan
Reputation 2,160
#2 JP1956
JP1956
Reputation 1,640
#3 Jonathan Ford
Jonathan Ford
Reputation 1,570
View All

Related Models For Sale

Used Honda Civic
297 Great Deals out of 4,187 listings starting at $1,291
Used Toyota Camry
43 Great Deals out of 1,606 listings starting at $1,700
Used Honda Accord Coupe
15 Great Deals out of 370 listings starting at $3,950
Used Nissan Altima
65 Great Deals out of 1,277 listings starting at $2,750
Used Nissan Maxima
27 Great Deals out of 329 listings starting at $3,976
Used Toyota Corolla
155 Great Deals out of 3,424 listings starting at $2,500
Used Honda CR-V
57 Great Deals out of 2,711 listings starting at $995
Used Acura TL
21 Great Deals out of 275 listings starting at $2,700
Used Hyundai Sonata
43 Great Deals out of 1,310 listings starting at $2,490
Used BMW 3 Series
146 Great Deals out of 1,904 listings starting at $2,300
Used Dodge Charger
78 Great Deals out of 846 listings starting at $1,999
Used Kia Optima
43 Great Deals out of 758 listings starting at $6,495
Used Ford Fusion
155 Great Deals out of 2,071 listings starting at $1,888
Used Chevrolet Malibu
110 Great Deals out of 2,272 listings starting at $2,500
Used Ford Mustang
9 Great Deals out of 1,212 listings starting at $2,995

Used Cars For Sale

2017 Honda Accord LX For Sale
40 listings starting at $24,490
2016 Honda Accord LX For Sale
14 listings starting at $19,995
2015 Honda Accord LX For Sale
11 listings starting at $14,700
2014 Honda Accord LX For Sale
19 listings starting at $14,845
2013 Honda Accord LX For Sale
30 listings starting at $12,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.