Idle Mixture Inspection

WARNING: This page is about a different car, the 2002 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.

Perform "Engine Tune-up Preparation". (See ENGINE TUNE-UP PREPARATION .)
Verify that the idle speed and ignition timing are within the specification. (See 01-10-33 Ignition Timing Inspection.)
Warm up the engine by holding the engine speed at 2,500-3,000 RPM for approx. 3 minutes .
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 ON-BOARD DIAGNOSTICS .)
  - HO2S. (See HEATED OXYGEN SENSOR .)
  - Intake manifold vacuum. (See INTAKE-AIR SYSTEM FLOW DIAGRAM .)
  - Fuel line pressure. (See FUEL PRESSURE (EXCEPT B2300, B3000, B4000 & TRIBUTE .)
  - Ignition timing control. (See IGNITION TIMING INSPECTION .)
- If the systems and devices are normal, replace the TWC. (See EXHAUST SYSTEM REMOVAL/INSTALLATION .)