High CO and HC - at High RPM

This condition is indicated by abnormally high carbon monoxide and hydrocarbon emissions during cruise (2500 rpm).

^ EEC system malfunction.
- Perform EEC QUICK TEST. QT4 Perform Diagnostic Test Mode (Extracting Codes)
^ Electrical misfires.

- Check ignition system. Testing and Inspection

^ Vacuum leak.

- Check vacuum lines and routing, also check intake manifold and vacuum components.

^ Faulty canister purge system.

- Check evaporative emission control system. Testing and Inspection

^ PCV malfunction.

- Check PCV system. Testing and Inspection

^ EGR malfunction.

- Check EGR system. Testing and Inspection

^ Restricted exhaust.

- Check catalytic converter. Testing and Inspection

^ Initial timing incorrect.

- Check ignition timing. Adjustments

^ Verify vehicle remains in closed loop at steady throttle (2500 rpm) and oxygen sensor is working.
- Perform HO2S Monitor Test. QT10 Perform HO2S Monitor Test