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Engine Control System Self-Diagnostics - 4-Cylinder
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DTC P0420: Catalyst System Efficiency Below Threshold (CALIF. Emissions)
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Notes
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DTC P0420: Catalyst System Efficiency Below Threshold (CALIF. Emissions): Notes
NOTE:
Air/Fuel (A/F) sensor refers to sensor closest to engine block. Heated oxygen sensor No. 2 refers to sensor farthest from engine block.