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

79,185

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

Honda Accord Experts

  • #1
    Tom Demyan
    Reputation
    2,380
  • #2
    JP1956
    Reputation
    1,890
  • #3
    dandyoun
    Reputation
    1,640
View All

Related Models For Sale

Used Toyota Camry
1,124 Great Deals out of 76,738 listings starting at $1,100
Used Honda Civic
600 Great Deals out of 52,409 listings starting at $999
Used Nissan Altima
1,155 Great Deals out of 74,276 listings starting at $900
Used Honda Accord Coupe
138 Great Deals out of 5,020 listings starting at $1,995
Used Nissan Maxima
330 Great Deals out of 20,467 listings starting at $1,400
Used Toyota Corolla
942 Great Deals out of 70,520 listings starting at $1,479
Used Honda CR-V
711 Great Deals out of 63,714 listings starting at $1,495
Used Hyundai Sonata
593 Great Deals out of 54,267 listings starting at $1,500
Used Acura TL
96 Great Deals out of 4,092 listings starting at $1,991
Used Dodge Charger
318 Great Deals out of 36,216 listings starting at $1,999
Used BMW 3 Series
1,141 Great Deals out of 34,047 listings starting at $1,209
Used Chevrolet Malibu
1,009 Great Deals out of 53,938 listings starting at $1,599
Used Kia Optima
486 Great Deals out of 31,982 listings starting at $2,450
Used Ford Mustang
348 Great Deals out of 41,846 listings starting at $1,488
Used Mazda MAZDA6
182 Great Deals out of 11,858 listings starting at $1,200

Used Cars For Sale

2016 Honda Accord LX For Sale
14 Great Deals out of 691 listings starting at $11,199
2015 Honda Accord LX For Sale
55 Great Deals out of 2,524 listings starting at $9,495
2014 Honda Accord LX For Sale
30 Great Deals out of 912 listings starting at $8,500

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.