Fails emission test (MIL works OK, no DTCs set)
Diagnostic procedure
Except KP (Argentina), KX models:
Inspect the three way catalytic converter (TWC).
Except KP (Argentina), KX models:
Check the spark plugs.
Test the fuel pressure.
Except KP (Argentina), KX models:
Test the injectors.
Check the EVAP system.
Troubleshoot the VTEC system oil pressure.
Also check for
Fuel contamination
Low compression
Broken cam chain