1993 Honda Civic EH2 with JDM D15B VTEC - Failed emissions...Diagnose this....??


I really have a 93...doh!
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So I have a JDM D15B VTEC in an EH2 automatic (93 Honda Civic DX Hatch) and up here in Canada I failed emissions testing two times already. I would like your guys help in diagnosing what is going on. I'm leaning towards bad catalytic converter + oxygen sensor (and possibly bad ignition timing) but here is what was done up to this point. BTW: The car was kept in the garage for about a year and a half sitting doing nothing. But I want opinions first before shelling out $$ for both parts.

3 years back Pass.

Test 1: Did nothing but went to emissions test, failed only CO%.

Test 2: Cleaned PCV valve, changed oil/filter, seafoam, high octane, ran the car hot until test. Failed, much worse this time. Almost failed NO ppm as well. Three things failed and forth almost failed. The seafoam must have facked up the O2 sensor which facked up the cat. But then again the cat is probably too old. Thats why I smell something bad when the car is idling.

Definitely check the cat. Possibly replace it. Is your car throwing codes for the o2 sensors?

I believe high octane additives will spike your ppm's dramatically. Someone correct me if i'm wrong.

My thoughts? Clear your car's computer and let it rebuild its basemaps. Link in sig. Try to use medium or premium gas too. It runs a little leaner overall.

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