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Home >> Subaru >> 2018 >> Outback 2.5i >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (P0171 To P0685) (H4DO) >> Diagnostic Procedure With Diagnostic Trouble Code (DTC) >> DTC P0420: Catalyst System Efficiency Below Threshold Bank 1 >> Execution Condition
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Execution Condition

Secondary parameters Execution condition
Battery voltage ≥ 10.9 V
Barometric pressure ≥75.1kPa (563mmHg, 22.2inHg)
Amount of intake air < 7.5g/s (0.26oz/s)
Accelerator pedal position While idling
Rear oxygen output voltage after fuel cut < 0.15V
Estimated catalyst temperature ≥550°C (1022°F)
Estimated temperature of the rear oxygen sensor element ≥500°C (932°F)
(Integrated intake air amount during fuel cut
Fuel shut-off function from above)
≥12.95g (0.46oz)(1)
Not in operation
(1) 5 seconds or more of fuel cut