When is the tailpipe (idle) smoke test performed during a BAR97 inspection?

The tailpipe (idle) smoke test is conducted after the tailpipe sampling part of the test because it is specifically designed to assess the emissions produced by the vehicle at idle. By performing the smoke test after measuring the emissions, inspectors can evaluate any visible smoke that may be emitted from the tailpipe under specific conditions. This timing allows for a clearer understanding of the vehicle's overall performance regarding emissions and ensures that the results from the tailpipe sampling inform any necessary follow-up evaluations or repairs.

Conducting the smoke test after tailpipe sampling ensures that any observed smoke can be correlated with the initial emissions data. This is crucial for identifying potential problems in the vehicle's combustion or exhaust system that might not be evident when examining other components of the emissions system.