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Inspection Mode V

DTC Item Condition Number of driving cycles on the detecting condition
P0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD BANK 1 - 2
WARNING: When performing inspection mode V on a public road, pay sufficient attention to the traffic condition and give the highest priority to safe driving.
NOTE: Perform the inspection mode after warming up the engine except that the engine coolant temperature at engine start is specified.
  1. Drive according to the drive pattern described below.
    G13202321Courtesy of SUBARU OF AMERICA, INC.
    NOTE:
    • The condition of acceleration or constant driving can be changed according to different traffic conditions. 
    • If diagnostic values have not been input after driving, repeat the cycle from step (C) without stopping the engine. 
  2. Read the temporary code using the Subaru Select Monitor or general scan tool. Ref. to COMMON (DIAG)>DIAGNOSTIC TROUBLE CODE (DTC) .