Downstream of the catalytic converters

CAUTION: The exhaust emissions must be checked in the open or where this is not possible, in a suitable environment equipped in accordance with the current safety laws.

NOTE: This test must be carried when the engine is at normal running temperature (i.e. when the electric cooling fan has cut in and then cut out again. If the Idle speed is not within the specified limits, check that the constant Idle speed actuator is functioning correctly.

Downstream of the catalytic converters

• Check that the oil is at the correct level and that the air cleaner cartridge is clean.
• Start the engine and run it at idle speed.
• Insert the probe of the analyzer into the end of the exhaust pipe and check that the percentage of CO and the quantity of unburnt hydrocarbons (HC) are within the specified limits.

• If the test results in values which are not within the specified limits, make the necessary adjustments by using a screwdriver to move the trimmer after removing the the sealed cap with an appropriate tool.

1. Idle CO trimmer
2. Sealed cap
3. Regulation screw

• When the adjustment has been made, check that the idle speed has not been altered and if it has, restore it to its original value by moving the by-pass screw on the throttle body. Check that the CO and HC values have not been altered.