2003 Huyndai Accent won't pass smog?

Asked by Sep 05, 2012 at 05:49 PM about the 2003 Hyundai Accent GL

Question type: Maintenance & Repair

I have a 2003 Hyundai Accent that recently did not pass smog (CA). mechanic suggested new spark plugs, repaired, came back, no luck. High NOX?  Anyhow, he stated that is was the catalytic converter, but that there is no aftermarket part, only dealer part. When I call the dealer to inquire about part purchase, they ask if the check engine light was on to indicate catalytic converter, otherwise, they say I should get a 2nd opinion since the part is non-refundable and installing it won't guarantee that the car will pass smog. Any other ideas as to what is causing the high NOX (?) value, I was told that an oxygen sensor alone won't help and we would probably need to replace that along with the catalytic converter.. Any suggestions? One small detail: my daughter accidentally put 1/2 gallon of diesel into her car 8 months ago (ran out of gas, went into dads garage and filled from gas container that she didn't realize was not gas) , it bogged and smoked like a dog until it was out, but no other apparent mechanical issues. we did change the spark plugs and fuel filter after that..Any suggestions?

2 Answers


i am an emissions inspector in connecticut, a 2003 car doesnt have to run on the dyno so the nox gas has nothing to do with you failing emissions. the reason you are failing as far as CT is concerned is because of the check engine light and whatever those codes are. get those fixed and you will pass

1 of 1 people found this helpful.

Have the EGR system inspected. For leaks a stuck open valve or large Carbon build, if it is cleaned out by your shop. Run a fuel system treatment. I stand by techron intake system cleaner, run your tank down to E add in Cleaner( after any service) and fill with plus or super fuel. Run the tank back Down on E to complete treatment. I've seen cars here in Massachusetts fail box for something as simple as cleaning the throttle body.

Your Answer

Hyundai Accent Experts

  • #1
  • #2
  • #3
    Tom Demyan
View All

Related Models For Sale

Used Hyundai Elantra
551 Great Deals out of 46,516 listings starting at $999
Used Toyota Corolla
942 Great Deals out of 70,520 listings starting at $1,479
Used Honda Civic
600 Great Deals out of 52,409 listings starting at $999
Used Hyundai Sonata
593 Great Deals out of 54,267 listings starting at $1,500
Used Honda Accord
801 Great Deals out of 89,314 listings starting at $1,444
Used Nissan Sentra
682 Great Deals out of 53,550 listings starting at $1,800
Used Ford Focus
605 Great Deals out of 69,890 listings starting at $1,495
Used Kia Rio
42 Great Deals out of 6,098 listings starting at $1,995
Used Toyota Camry
1,125 Great Deals out of 76,738 listings starting at $1,100
Used Mazda MAZDA3
250 Great Deals out of 27,360 listings starting at $1,495
Used Toyota Yaris
46 Great Deals out of 2,627 listings starting at $2,433
Used Ford Fiesta
124 Great Deals out of 16,813 listings starting at $2,400

Used Cars For Sale

2018 Hyundai Accent For Sale
2,047 listings starting at $12,599
2017 Hyundai Accent For Sale
124 Great Deals out of 3,498 listings starting at $7,995
2016 Hyundai Accent For Sale
61 Great Deals out of 3,370 listings starting at $6,995
2015 Hyundai Accent For Sale
19 Great Deals out of 661 listings starting at $6,390
2014 Hyundai Accent For Sale
29 Great Deals out of 652 listings starting at $4,991

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.