Idle Mixture Inspection

WARNING: This page is about a different car, the 2005 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.

Perform "Engine Tune-up Preparation".
Verify that the idle speed and ignition timing are within the specification. (See IGNITION TIMING INSPECTION .)
Insert an exhaust gas analyzer to the tailpipe.
Verify that the CO and HC concentrations are within the specified limits.
- If not within the specified limits, inspect the following:
  - On-board diagnostic system (See 01-02A-13 ON-BOARD DIAGNOSTIC TEST.)
  - HO2S (See HEATED OXYGEN SENSOR (HO2S) INSPECTION .)
  - Intake manifold vacuum (See INTAKE MANIFOLD VACUUM INSPECTION .)
  - Fuel line pressure (See FUEL LINE PRESSURE INSPECTION .)
  - Ignition timing control (See IGNITION TIMING INSPECTION .)
    - If the systems and devices are normal, replace the TWC. (See WARM-UP THREE-WAY CATALYTIC CONVERTER (WU-TWC) INSPECTION .)