1992 Honda Integra Failed NOx Smog

1992 HONDA
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MJMJ
  • MEMBER
  • 1 POST
Hi guys,

My dependable 1992 Integra(GS, automatic) failed CA smog test this time:
a) it failed in NOX column for 25 mph at a test-only station. I changed oil/oil filter before I went in.
b) I took it to my mechanic who changed the converter on the car. I drove more than 30 minutes and have it tested again.
c) It failed again in NOX, now for both 15mph and 25 mph tests.
d) My mechanic wants to change converter again, he contents that the new converter should not make it worse.
e) He mentioned there is a GPE(?) part that might have clogged lines in there and cause the smog test fail. He said Honda has a repair kit for this problem, and that will be the next thing he's going to test.

Is my mechanic's assertion of the converter is correct?
Is my mechanic suggested course of action valid in this case?

Also my car had a problem that after driving from 2 to 30 minutes the 'check engine' light comes on, but it was never on when I take my car to the mechanics. He says he cannot check the computer code unless the light is on at the "scan" time. Is he correct?
I heard this is a known problem with old Honda/Accura cars, could you shed some light on this?

Mucho Thanks.

Michael :shock: :?: :?: [img][/img]
Apr 4, 2006 at 8:04 AM
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LOSONE
  • ✓Experienced Mechanic
  • 1,616 POSTS
The computer stores the info for a check engine light. A mechanic with good equipment shoud be able to check it.

The converter is good. NOX is caused by a rich engine. There is something wrong that is making the engine run rich. Take it too another mechanic and see what code has been set. That will answer the questions
Apr 4, 2006 at 8:13 AM
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TIMINGISEVERYTHING
  • MEMBER
  • 17 POSTS
Here are a couple things that have worked for me even with a bad cat:
1. Fill up with 91 octane (or higher if possible)
2. Toss 2 moth balls in the fuel tank.
3. Clean off Air Density Sensor in the intake
4. Make sure the car has new plugs, wires, cap, rotor(if applicable)
5. Drive like a bat out of hell for a couple minutes then disconnect the battery for 10 minutes to reset the computer of all the fuel mapping information. This step makes the car restart the fuel mapping and has to figure out what fuel you are even running.

With these few simple things, I have passed type 2 smog with a known bad catalytic converter on a Honda Accord.
Apr 5, 2006 at 10:07 AM

Suggested Repair

Have a shop with proper equipment retrieve stored check-engine codes even if the light is off. High NOx points to a rich-running condition, so diagnose that cause before replacing the catalytic converter again.

Conversation Summary

A 1992 Honda Integra failed a California smog test for NOx and failed again after a catalytic converter was replaced. The mechanic proposed another converter and a possible clogged-line repair kit, and said codes could not be read unless the check-engine light was on. The expert said stored codes can be retrieved with proper equipment, the converter is not the problem, and a rich-running condition should be diagnosed by another mechanic.

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