Section 216 (Engine Mechanical): Co/HC: Inspection

WARNING: This page is about a different car, the 2004 Toyota MR2, 2003 Toyota MR2, and 2002 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: This check is used only to determine whether or not the idle CO/HC complies with regulations.

INITIAL CONDITIONS
1. Engine at normal operating temperature
2. Air cleaner installed
3. Air 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 check 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

Fig 1: Measuring HC/CO At Tailpipe
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
IMMEDIATELY CHECK CO/HC CONCENTRATION AT IDLE AND/OR 2,500 RPM
Complete the measuring within 3 minutes.

NOTE: When doing the 2 mode (idle and 2,500 RPM) test, follow the measurement order prescribed by the applicable local regulations.

If the CO/HC concentration does not comply with regulations, troubleshoot in the order given below.
- Check heated oxygen sensor operation (See DTC P0130: HEATED OXYGEN SENSOR CIRCUIT (BANK NO. 1 SENSOR NO. 1) OR DTC P0150: HEATED OXYGEN SENSOR CIRCUIT (BANK NO. 2 SENSOR NO. 1) in appropriate ENGINE PERFORMANCE - FAULT ISOLATION article.
- See the table below for possible causes, then inspect and correct the causes if necessary.
  
  Fig 2: Identifying Causes Of High HC/CO Problems
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002