Emissions Question

[ELM'sLX+CHL'sDX]

Hey Guys:

Today I got my smog check. I passed but my HC levels were a bit high. Any idea what is causing this?

Would new spark plugs and having the valve adjusted bring the HC level down? Tech told me that this might be indicative of a failing cat-converter. Any help is appreciated.

Thanks,
Claude

[Jareds 89 LX-i]

You're up over 300k now, right? If that's still the original cat converter, I'd definitely suspect that. I'm trying to remember, I took the test right after I got a new cat (after previously failing) and one of the readings went down, but I can't remember which one, and I still failed. I want to say it was the HC though, but can't remember for sure.

[cruznz]

causes for higher- than- normal HC readings.....

1/ rich or lean air-fuel mixture,
2/ improper ignition timing,
3/ engine probs,...(blow-by, worn rings,burned valves, head gasket),
4/ faulty emission control sys,( faulty PCV, cat convertor,evaporative control sys),
5/ ignition syst troubles,(plugs, dist cap,leads)