Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine Mechanical: Co/HC: Inspection
HINT:
This check is used only to determine whether or not the idle CO/HC complies with regulations.
- INITIAL CONDITIONS
- The engine is at normal operating temperature.
- Air cleaner is installed.
- All pipes and hoses of the air induction system are connected.
- All accessories are switched OFF.
- All vacuum lines are properly connected.
HINT:
All vacuum hoses should be properly connected.
- SFI system wiring connectors are fully plugged.
- Ignition timing is set correctly.
- Transmission is in neutral range.
- Tachometer and CO/HC meter are calibrated by hand.
- START ENGINE
- RACE ENGINE AT 2,500 RPM FOR APPROX. 180 SECONDS
- INSERT CO/HC METER TESTING PROBE AT LEAST 40 cm (1.3 ft) INTO TAILPIPE DURING IDLING
- IMMEDIATELY CHECK CO/HC CONCENTRATION AT IDLE AND/OR 2,500 RPM
HINT:
When performing the 2 mode (2,500 RPM and idle) test, follow the measurement order prescribed by the applicable local regulations.
- TROUBLESHOOTING
If the CO/HC concentration does not comply with the regulations, perform troubleshooting in the order in Fig 2 .
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.