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calling the smog gurus

hi I just failed the good ole california smog test i have a 98 civic EX manual

109K i failed with high HC tthe first time around cause i just drove it in without doing anything since its never failed before after failing once I did new plugs, dist cap and rotor added 2 cans of heet to 1/4 tank of gas and ran for 15 miles on fwy prior to testing and it still failed the numbers dropped about 30 points on the HC with the tune up but still failed here are the #

co2 O2 HC CO

15 mph 13.7 .7 64max, test 99 .55max, test .16

25 mph 13.8 .5 47max, test 89 .54max, test .10

NO

477max , test 33 764max, test 13

had the computer scanned, no codes or pending codes engine is strong i dont think its blow by or anything like that, dont want to start throwing 90 dollar x2 02 sensors or 300 dollar cats without knowing what is the cause.

any insight would be appreciated

Reply to
hex
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"hex" wrote: 98 civic EX manual 109K

Failed california smog test - high HC.

Did new plugs, dist cap and rotor, added 2 cans of heet to 1/4 tank of gas and ran for 15 miles on fwy prior to retest. HC was about 30 points lower but still failed:

15 mph 25 mph Actual(Max) Actual(Max) CO2 13.7 13.8 O2 0.7 0.5 HC 99(64) 89(47) CO .16(.55) .10(.54) NO 33(477) 13(764)

No codes. Engine strong. Don't want to start throwing parts dollars at it without knowing the cause. Any insight appreciated. ________________________________________

Looks like it's still running too rich. If you do decide to throw parts dollars at it, start with a new air filter and plug wires.

Good luck.

Rodan.

Reply to
Rodan

The high HC means incomplete combustion. High CO means too much fuel, and high NOX emissions almost always indicate a problem with the EGR system. In this case your mixture looks okay as it is well within the test limits.

Adding heet (and 2 cans at that) to 1/4 tank of gas is the wrong approach to this problem. Heet is wood alcohol, and while what you did would likely help a carbureted engine pass an emission test by leaning the mixture, it will not have the same effect on a fuel injected engine. The computer will automatically adjust the fuel delivery to maintain a stochiometric mixture by introducing MORE fuel(since your alcohol mixture has less energy than gasoline), and thus the only effect you've made is to cut your gas mileage and take any water in the tank (which will be absorbed by the heet) and stick it into the combustion chamber(wood alcohol will bind to the water and drag it through the system), where it will not burn.

My advice: Fill up the tank with fresh gasoline to dilute the heet that you put in there and run it through again. I would also like to see the other numbers from your first pass through the test. Keep in mind at

109k you are probably due for oxygen sensors and a mass airflow sensor in the very near future.

And here's the clincher...if you drove the car with a misfire for any period of time it is also possible you destroyed the catalytic convertor, and if that is indeed your problem no amount of pouring stuff into the tank will get you through the test. Any shop can test the cat with a point -n- shoot thermometer. If after running for several minutes at a high idle RPM the inlet side of the cat is the same temperature as the outlet side then you can safely assume it is in need of replacement.

Good luck with it.

Chris

Reply to
halatos

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