This check is used only to determine whether or not the idle CO/HC complies with regulations.
- Engine at normal operating temperature
- Air cleaner installed
- All pipes and hoses of air induction system connected
- All accessories switched OFF
- All vacuum lines properly connected
- SFI system wiring connectors fully plugged
- Ignition timing set correctly
- Transmission in neutral position
- 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
When doing the 2 mode (2,500 rpm and idle) test, follow the measurement order prescribed by the applicable local regulations.
- Check heated oxygen sensors operation. (See page SF-72 )
- See the table below for possible causes, and then inspect and correct the applicable causes if necessary.
(Fluctuating HC reading)
(Black smoke from exhaust)
This guide is based on the book edition Toyota (RM502U, 1997)