Maintenance · ECOSAILWhat to Check When Catalyst Activity Declines
Higher outlet emissions do not automatically mean that the catalyst is exhausted. Injection faults, sensor drift, flow changes and higher engine-out emissions can produce similar symptoms.
Confirm the Change at Comparable Conditions
Compare inlet temperature, concentration, oxygen content, dosing and measurement basis at the same or similar load before dismantling the catalyst.
Separate Four Failure Mechanisms
Mechanical damage, chemical poisoning, thermal aging and deposits leave different evidence. Inspection should include the catalyst body, module seals, temperature history, fuel and lubricant records, and pressure-drop trend.
Rebuild the Baseline After Maintenance
After cleaning or replacement, establish a new baseline for inlet and outlet emissions, temperature, pressure loss and dosing so future decisions rely on trends rather than a single inspection.