PO420 and PO430 error codes

20

Asked by SonyaF40 Nov 14, 2018 at 09:11 AM about the 2003 Nissan Altima 3.5 SE

Question type: Maintenance & Repair

My vehicle started out with a slight miss and
decreased power on an incline. It is now missing
terribly, same power issue, strong fuel odor and
service engine light blinks off and on.

2 Answers

225

well first off if your engine light is blinking DO NOT drive it or even run it till you get these two codes fixed or else you could make it worse - the P0420 Code is: Catalyst System Efficiency Below Threshold Bank 1 and the P0430 Code is: Catalyst System Efficiency Below Threshold Bank 2 Possible causes for P0420 : Faulty Three-way Catalyst Converter Bank 1 Exhaust Tube Intake Air Leaks Faulty Oxygen (O2) Sensor Faulty Fuel injector(s) Leaking Fuel Injector (s) Faulty Spark plugs Improper Ignition Timing Faulty Engine Control Module (ECM) Dirty Air Filter Possible causes for P0430: Faulty Three-way Catalyst Converter Bank 2 Exhaust Tube Intake Air Leaks Faulty Oxygen (O2) Sensor Faulty Fuel injector(s) Leaking Fuel Injector (s) Faulty Spark plugs Improper Ignition Timing Faulty Engine Control Module (ECM) Dirty Air Filter i hope this helps.

2 people found this helpful.

Your Answer:

CarGurus Experts

  • #1
    Gene Arnett
    Reputation
    3,270
  • #2
    GuruB42YD
    Reputation
    2,450
  • #3
    GuruSY3ZL
    Reputation
    2,380
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Honda Accord
42 Great Deals out of 918 listings starting at $1,599
Used Toyota Camry
58 Great Deals out of 995 listings starting at $2,212
Used Nissan Maxima
11 Great Deals out of 146 listings starting at $5,653
Used Nissan Sentra
83 Great Deals out of 1,819 listings starting at $2,195
Used Honda Civic
176 Great Deals out of 3,762 listings starting at $1,995
Used Toyota Corolla
117 Great Deals out of 2,056 listings starting at $2,795
Used Chevrolet Malibu
47 Great Deals out of 1,133 listings starting at $1,295
Used Hyundai Sonata
35 Great Deals out of 1,107 listings starting at $3,112
Used Hyundai Elantra
156 Great Deals out of 3,577 listings starting at $2,995
Used Kia Optima
13 Great Deals out of 251 listings starting at $3,999

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. Content will be removed if CarGurus becomes aware that it violates our policies.