Engine Co/HC Emission Testing (5VZ-FE): Inspection

INITIAL CONDITIONS
1. Engine at normal operating temperature
2. Air cleaner installed
3. All pipes and hoses of air induction system connected
4. All accessories switched OFF
5. All vacuum lines properly connected
6. SFI system wiring connectors fully plugged
7. Ignition timing checked correctly
8. Transmission in neutral position
9. Tachometer and CO/HC meter 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 doing the 2 mode (2,500 RPM and idle) test, follow the measurement orders are prescribed by the applicable local regulations

Fig 1: Measuring CO/HC Concentration
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the CO/HC concentration does not comply with regulations, troubleshooting in the order given below.
1. Check the A/F sensor operation (See DTC P2195 OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 1 SENSOR 1), DTC P2196 OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 1 SENSOR 1) and DTC P2238 OXYGEN SENSOR PUMPING CURRENT CIRCUIT / LOW (FOR A/F SENSOR) (BANK 1 SENSOR 1), DTC P2239 OXYGEN SENSOR PUMPING CURRENT CIRCUIT / HIGH (FOR A/F SENSOR) (BANK 1 SENSOR 1) ).
2. See the Fig 2, and then inspect and correct the applicable causes if necessary.
  
  Fig 2: CO HC Concentration Problem Cause Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002