Exhaust gas analysis

EXHAUST GAS ANALYSIS

P4A58BJ01

Table summarizing pollutant emission tolerance values

Checking exhaust concentration of CO and HC

The concentration of carbon monoxide (CO) and unburnt hydrocarbons (HC) at the exhaust is measured by inserting a suitably calibrated sensor probe at least 30 cm into the end section of the exhaust pipe.

1. Check that the idle CO and HC concentration values are as recommended (see table).
2. If the HC value is outside of the recommended limits, whilst that previously measured upstream of the catalyzer was okay, then the engine parameters are taken to be correct and the cause of the problem should be sought in the decreased efficiency of the catalyzer.

CHECKING ENGINE IDLE SPEED

If the engine idle speed is not correct as the system is the self-adjusting type it is not possible to carry out any adjustment: therefore it is necessary to check that the accelerator linkage is correctly adjusted and therefore the problem should be sought by means of a complete fault diagnosis using the F/L Tester.

CHECKING IGNITION ADVANCE

In order to check the ignition advance values at different speeds it is necessary to use the F/L Tester diagnostic equipment.