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Emissions test failure

Perhaps someone can offer a second opinion on emissions diagnosis?

I recently acquired a 94 Eagle Summit / Mitsu Mirage with the 4G15 in very nice condition. 245,000km, compression 210 on all (192 nominal), no smoke on idle or acceleration. ie no reason to suspect rings or valve stem seals. Head may have been serviced in the last two years, as vacuum hoses are not original. Changed oil, set tappets, timing. I have the workshop manual, but emissions are not something I've needed to work on in detail before.

To sell the car in Ontario, I need an emissions test pass. Don't need one in Quebec where I live.

Test #1: Failed HC idle, 25/25 HC about 200% high, NOX and CO well within spec, passed all other requirements. New air filter, timing again. Test #2: Just passed HC idle, failed 25/25 load. Had the combustion chamber, valves and injectors cleaned with product called TerraKleen. Test #3: failed badly HC idle and 25/25, CO now way off. ie running very rich Reset ECU (theory: clean injectors now squirting too much fuel for current ECU parameters), ran for about 100km. Test #4: failed MISERABLY, worse than #3. ie still running very rich.

Front and Rear O2 sensors ($300 and $200 respectively) seem to be functional, ECU is not producing any error codes. Short of trying a new cat (next week), any suggestions on why the emissions got steadily worse?

Is 100km not enough for the ECU to reset it self and sort out the mixture control?

Stewart DIBBS

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Reply to
Stewart DIBBS
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Try this site, they have some information on emissions failure and corrective action.

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The above page is located at this site.

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Hope this helps, let us know how you made out.

Reply to
Nirodac Yar

stewart, is this a car you want to work on or are you stuck having to fix it? are there any E-85 stations in your area? i'd run a bunch of ethanol in your fuel and test again.

Reply to
simpleton

Sounds more like a bad cat than anything else. The injector cleaner probably did more damage to the cat and may have taken it out completely. If you read the cleaner bottle, they warn about this I believe. I know this is a problem with typical carbon/combustion cleaners. The chemicals are very similar.

You can try the temperature test on the cat. You basically measure the temperature going in and out of the cat. If there is more than a 200-300F degree difference, it is bad.

Reply to
Nobody U. Know

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