1993 Festiva failing CA Smog Check!

[dkfuel]

Greetings! I have a 1993 Ford Festiva with 122K miles and took it to get the California Draconian Bi-Annual Smog Check and it failed! The O2 and CO2 measurements are well within legal limits, but the HC and NO are dreadful. HC = 124 (Max is 99) and the NO = 1519 (Max is 738); both of these are from the 15 mph test. My mechanic said replace the CAT and move on with it.

Now this sounds logical and would probably cost about $250 for a "CA Legal" Universal CAT and labor (which is not horrible, considering the raping that occurs on newer cars with the "CA Legal" BS.) But a different mechanic once told me that throwing a new CAT on a problem when there could be other resolvable issues is lazy and just filtering a problem that could cause other issues.

Keeping that in mind, I tried doing the following:

1) Replaced the spark plugs with Iridium ones. The old ones looked really corroded.
2) Cleaned the MAF.
3) Replaced the O2 sensor.

That's all I could come up with based on an Internet Search for "car failed smog check." I had previously cleaned the Throttle Bottle before the Smog Check, if that means anything.

So I went back and had a "pre-test" done, which measures the emissions without the full test. It got WORSE. The HC is now 252 and the NO is now 2120. These are horrible values. I went back and checked the spark plugs and O2 sensor to make sure they were installed correctly. Now I should point out that one mistake I made after doing all of this (including the throttle body cleaning) was I did *not* unplug the battery to reset whatever ancient computer is in this guy. SO I've been driving it now (illegally since the registration expired in November) and I'm still noticing crappy gas milage. One thing that has changed is I no longer smell a lot of burning gas from the engine bay due to it running so rich.

I've been reluctant to go back for another pre-test because my mechanic is getting annoyed with it (not a fan of older cars.) But the fact that the gas milage is still bad makes me think not "enough" changed to pass.

I am open to suggestions. I love this car. I would hate to just throw a new CAT on it and pass emissions just to make the more important things (gas milage, etc.) quickly deteriorate. The car is in fantastic condition otherwise.

Thanks in advance!
William

[WmWatt]

I have the carburetted model. NO2 on mine is controlled by the EGR (exhaust gas recurculation) valve which cools the combustion chamber to lower the formation of NO2. Easy to remove and clean with solvent. When dirty the plunger sticks and it doesn't open as it should. Don't know what the equivalent is on the fuel injected model. Sorry.

AFAIK hydrocarbons are just unburnt fuel in the exhaust. Your "rich" and "smell" would seem to agree. How's the compression, timing, injectors?

[dkfuel]

Hi and thanks for the response. Yes, unfortunately this model has no EGR value. My mechanic (who also does the smog check) checked the timing and it was the correct value. He said he could adjust the MAF but it would not help enough to drop these terribly high numbers. I haven't had a compression check and am also not sure how to check the fuel injectors. I'm guessing a mechanic would have to do the compression check - are fuel injectors something I can manage? Should I buy the fuel injector cleaner you can add to gasoline or is that futile in this case?

Thanks again.

[LordOfTheCars]

NOx is the EGR not opening or timing to far advanced

HC is un-burned fuel. Too rich or possibly a shade lean. (lean misfire can show up this way.)

Check the CAT with a surface pedometer. It should be much hotter than the head tube of the exhaust if it's working right..

I can't remember is the harmonic balancer is on a rubber ring on these motors. If it is the the outer ring can slip and setting timing with one that has slipped can be a problem.

I was a Smog tech in California for over 20 years before I left the state for some place sane.

[Rick the Quick]

I've run dozens of cars through the New Mexico/ Bern.Co. test and one thing I know will most always bring the HC level down is a new set of plugs, plug wires and cap and rotor. High HC can also indicate a worn engine / low compression although I have had engines with a weak (85 PSI} cylinder pass. The other cylinders had good compression BTW. One other thing that may help you is to bring the idle speed up as high as the test allows. Here in New Mexico they allow up to 1200 rpm idle speed.I would jack my idle up to 1100-1150 rpms before having the car tested. Make sure the car is good and hot before you bring it in for testing. Find a good pull on the Interstste, a long hill that requires full throttle for several minutes. It sounds like you are not far off on the HC levels. As for the NOx I can't remember if they were even part of the test in my county. I do remember HC and CO. Being poor and owning many a jalopy I found a permanent fix to the emission test headache : register my cars out of county. If I lived in California I would look into registering my vehicles in another state. It shouldn't be to difficult to achieve dual citizen status.Just like I have. I am now officially a senior and living on a fixed income I have been forced to rent my house while I live out of county because it is less expensive and as an added bonus NO Emission testing!