1989 Honda Civic NOX readings on Emissions

1989 HONDA CIVIC
180,000 MILES • 4 CYL • 2WD • MANUAL
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BKI7433
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  • 2 POSTS
My car failed this years Emissions Test with a high NOX reading. My car is a 1989 Honda Civic HB with a 1.5 engine, 4spd. Does it have an EGR and where is it? What else may be the problem for a high NOX reading?

Please Help,
Keith
Sep 30, 2010 at 11:57 PM
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KHLOW2008
  • ✓Experienced Mechanic
  • 41,812 POSTS
Hi bki7433,

Here are a list of possible causes.

Misfire condition
Malfunctioning or improperly adjusted EGR valve
Failed oxygen sensor
Leak in exhaust tubing upstream of converter
Excessive carbon deposits in combustion chamber
Improper spark advance
Blocked coolant passage
Overly lean air-fuel mixture
Damaged cold air duct
Failed or malfunctioning catalytic converter
Corroded or damaged engine sensor electrical connections

EGR valve is at rear of engine but 'I could not find any diagrams to indicate the location.
Oct 1, 2010 at 2:18 AM
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