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Compass Limited
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Engine Performance
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2.0L - DTCS P0405 To P042E
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DTC Troubleshooting
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P0420 Catalyst System Efficiency Below Threshold Bank 1
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Set Condition
Set Condition
The Powertrain Control Module (PCM) detects a failed catalyst if the final Downstream O2 Sensor state of change test ratio is greater than the calibrated fail threshold.