Ontario E-Test Failure: Is It the Engine, Exhaust, or Emissions System?
A failed emissions test does not automatically mean there is a major engine problem. A diesel commercial vehicle can fail because of an issue in the engine, exhaust system, or emissions-control equipment. Knowing where the problem starts makes the repair process much clearer. Ontario's emissions program for applicable heavy-duty diesel commercial vehicles includes a pre-test inspection, an opacity test, and an on-board diagnostic test for certain vehicles. ( ontario.ca ) Start With the Actual Test Result The first step after a failed e-test result is to identify what part of the inspection caused the failure. Guessing that the engine is responsible can lead to unnecessary repairs. An opacity test measures how much light is blocked by exhaust smoke. Ontario uses different opacity limits based on vehicle model year, with vehicles from 2011 and newer subject to a 10% limit. Certain heavy-duty diesel vehicles also undergo OBD testing. The system checks emissions-related fun...