Catalyst Monitoring: Notes

The diagnosis of the catalyst directly determines the OSC (oxygen storage capacity) of the catalyst and compares the result with the oxygen storage capacity of a borderline catalyst (catalyst deteriorated to the malfunction criteria). The nonlinear correlation between conversion efficiency and oxygen storage capacity has been shown in various investigations.

The diagnosis is split into a quickpass check and the main catalyst check. The quickpass check is only able to diagnose a good catalyst. Malfunctions can only be detected by the main catalyst check.