Failed Emissions barely

[vectormechanic]

I just failed my second emissions test due to HC. But I am getting over 46 mpg. After my first test, I did new thermostat (Motorcraft 2-stg), denso O2, cap and rotor (brass), 2 oil changes, air filter. I did not change plugs because they were only about a year, maybe 2 years old, and in pitch dark, I was seeing no sparks or blue buzz, but I suspect the wires are weak or resistive because I bet a donut they are original. I burn some oil, yet I get 46+ mpg..go figure. I am going to change the plugs and wires and look into the coil, timing and secondary ground thing.
Whoa! I just re-read the report - I am only failing at idle, and I am getting 131, the limit being 130! And they wanted to sell me a waiver! Pshaw!
So all you good neighbors, what do you suppose is the most likely culprit if I am getting hi HC at IDLE?

Now this is getting interesting. Here is a table of my story:

HC ppm HC Limit ppm
First test, idle 189 130
First test, 2500 rpm 90 130

2nd test, idle 131 130
2nd test, 2500 rpm 94 130

All the other results did not change much, if anything, they were a little higher in the 2nd test. Btw, my PCV valve is not brand new, but pretty new, and my intake is clean and dry.

[bravekozak]

Pour a bottle of "Guaranteed to Pass" in your gas tank.

[Grey Vw]

Turn your idle down a bit? Just a guess. I would just go try again and hope the numbers are different

[perucho]

At idle vacuum is strongest, may be getting more oil through. Get your car as hot as possible and have it tested that way. It helps lower HC readings.

[villageidiot]

run that thing for a superblast down the highway for 10 miles or so, then pull it right into the station

[JohnGunn]

Though almost no one seems to have discovered it, cleaning a catalytic converter will dramatically improve its effectiveness.

See the results when I cleaned the cat of my own Festiva after it failed the California inspection. Full report contained in the following post:

http://www.fordfestiva.com/forums/showpost.php?p=359526&postcount=2

If you decide to try this, please report back your results. This is information that needs to be better known.

Good luck.

John Gunn
Coronado, CA

[getnpsi]

If your NO was in line and its just your HC, I'd try some water mist into the intake, with 2 gallons of e85 in your mix. The cat cleaning seems to also just help the HC so do it all. Good luck.