Mechanics

MY CAR FAILED THE STATE EMISSIONS TEST WITH HIGH HC READINGS

2003 Hyundai Tiburon • 126,000 miles

Hi guys, so my 2003 hyundai tiburon was taken in for emissions last monday and it failed. The readings on the sheet came up as HIGH HC READINGS: HIGH HC READINGS ARE A RESULT OF UNBURNED OR PARTIALLY BURNED FUEL
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Ironwing777
May 12, 2012.




Well I took my 2003 hyundai tiburon to have emissions testing done on it and it failed due to High NOx readings. It states here on this test sheet that High NOx readings are the result of high combustion temperatures and/or High combustion pressures. So My step dad had suggested we had it looked at and the mechanic said that the catalytic converter and O2 sensor need to be replaced. Also something about the spark plugs and he was going to take a look at the vacuum hoses. But overall I was seeking a second opinion as to what you guys think my problem might be not passing the NOx GPM part of the test. Also my check engine light is on (the girl I bought it from said it turned on when they put a new header on) not sure if that was the truth but anyways, it also idles wierd sometimes when I start it up, it will start fine and then it idles up and down so I give it a little rev and its good it does that periodically at stop lights as well. Oh and I cant forget the girl I bought it from also mentioned when they put in the high performance exhaust they had removed the O2 sensor, but yes on the emissions test it had passed so I thought it was wierd but I have no clue. Well I hope you guys have some tips for me and I do really appreciate you guys taking the time to help me out!

Thanks,
Seth

Tiny
Ironwing777
May 12, 2012.
First of all, it has to have both sensors installed. One being gone will cause a light.

Second, they may have gutted or installed an aftermarket cat which rarely work because there is not enough precious metals.

We would also like the code numbers for the failure as well.

And finally, they are right about the high NOX. In most cases, it is the converter that is not doing its job.

Roy

ASEMaster6371
May 12, 2012.
Ok that reminds me the mechanic said that when he took a look at the catalytic converter he said they had gutted it out, and im not sure what you mean by code numbers for the failure.

Tiny
Ironwing777
May 12, 2012.
If you have a report, there should be numbers listed on there for the failure. What state are you residing?

Roy

ASEMaster6371
May 12, 2012.
The reading numbers? (3.0639) Limit: 1.5000, I live in Colorado.

Tiny
Ironwing777
May 12, 2012.
Or I have these other numbers on the other side it says 0420, catalyst system efficiency below threshold (bank 1)
and 0107, MAP/Barometric Pressure circuit low input.

Tiny
Ironwing777
May 12, 2012.
No, they are the readings. I am looking for the code numbers like 420, 300 etc

Roy

ASEMaster6371
May 12, 2012.
0402: Catalyst system efficiency below threshold.
0107: MAP/Barometric pressure circuit low input.

Hope those are the right ones.
AD

Tiny
Ironwing777
May 12, 2012.
Good, the first should be 420 and that is the cat code. It needs to be replaced.

The next one is the mass air flow sensor code. First, you need to verify it is actually there and hooked up. Then you need to see if there are any leaks in the hose between the mass air flow and the throttle body.

Roy

ASEMaster6371
May 12, 2012.
Or yeah 0420 not 0402 haha

Tiny
Ironwing777
May 12, 2012.

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