Check exhaust system for damage or exhaust leaks. If exhaust system is okay, replace catalytic converter. Clear DTCs. Road test vehicle to verify repairs. If DTC P0420 resets, replace PCM.
Home/Mitsubishi/Eclipse/Mitsubishi Eclipse II (1994-1999)/Repair manual/Testing & Diagnostics/DTC P0420 - CATALYTIC CONVERTER EFFICIENCY BELOW THRESHOLD
Contents
Wiring diagrams Section: Testing & Diagnostics- Engine Controls - System/component Tests - 2.0L Turbo: Diagnosis
- Engine Controls - System/component Tests - 2.0L Turbo: Other
- Engine Controls - Tests W/codes - 2.0L Turbo: Overview
- Engine Controls - Tests W/codes - 2.0L Turbo: Diagnosis
- Engine Controls - Tests W/codes - 2.0L Turbo: Component Locations
- Engine Controls - Tests W/codes - 2.0L Turbo: Other
- DTC P0100 - VOLUME AIRFLOW (VAF) CIRCUIT MALFUNCTION
- DTC P0105 - BAROMETRIC PRESSURE CIRCUIT MALFUNCTION
- DTC P0110 - INTAKE AIR TEMPERATURE (IAT) CIRCUIT MALFUNCTION
- DTC P0115 - ENGINE COOLANT TEMP (ECT) CIRCUIT MALFUNCTION
- DTC P0120 - THROTTLE POSITION (TP) CIRCUIT MALFUNCTION
- DTC P0125 - EXCESSIVE TIME TO ENTER CLOSED LOOP FUEL CONTROL
- DTC P0130 - FRONT HO2S CIRCUIT MALFUNCTION
- DTC P0135 - FRONT HO2S HEATER CIRCUIT MALFUNCTION
- DTC P0136 - REAR HO2S CIRCUIT MALFUNCTION
- DTC P0141 - REAR HO2S HEATER CIRCUIT MALFUNCTION
- DTC P0170 - FUEL TRIM MALFUNCTION
- DTC P0201, P0202, P0203 OR P0204 - INJECTOR NO. 1, 2, 3 OR 4 CIRCUIT MALFUNCTION
- DTC P0300 - RANDOM MISFIRE DETECTED
- DTC P0301, P0302, P0303, OR P0304 - CYLINDER NO. 1, 2, 3 OR 4 MISFIRE DETECTED
- DTC P0325 - KNOCK SENSOR (KS) NO. 1 CIRCUIT
- DTC P0335 - CKP SENSOR CIRCUIT MALFUNCTION
- DTC P0340 - CMP SENSOR CIRCUIT MALFUNCTION
- DTC P0400 - EXHAUST GAS RECIRCULATION (EGR) FLOW MALFUNCTION
- DTC P0403 - EXHAUST GAS RECIRCULATION (EGR) FLOW MALFUNCTION
- DTC P0420 - CATALYTIC CONVERTER EFFICIENCY BELOW THRESHOLD
- DTC P0421 - WARM-UP CATALYTIC CONVERTER EFFIC BELOW THRESHOLD
- DTC P0440 - EVAPORATIVE (EVAP) CONTROL SYSTEM MALFUNCTION
- DTC P0442 - EVAPORATIVE (EVAP) CONTROL SYSTEM LEAK DETECTED
- DTC P0443 - EVAP CONTROL SYSTEM PURGE CONTROL VALVE CIRCUIT MALFUNCTION
- DTC P0446 - EVAP CONTROL SYSTEM VENT CONTROL MALFUNCTION
- DTC P0500 - VEHICLE SPEED SENSOR (VSS) MALFUNCTION
- DTC P0505 - IDLE CONTROL SYSTEM MALFUNCTION
- DTC P0510 - CLOSED TP SWITCH MALFUNCTION
- DTC P0705 - TRANSMISSION RANGE SENSOR CKT MALFUNCTION (A/T)
- DTC P0710 - TRANSMISSION FLUID TEMP SENSOR CKT MALF (A/T)
- DTC P1103 - TURBOCHARGER WASTEGATE SOLENOID MALFUNCTION
- DTC P1104 - TURBOCHARGER WASTEGATE SOLENOID MALFUNCTION
- DTC P1105 - FUEL PRESSURE SOLENOID MALFUNCTION
- DTC P1300 - IGNITION TIMING ADJUSTMENT CIRCUIT MALFUNCTION
- DTC P1400 - MDP SENSOR CIRCUIT MALFUNCTION
- DTC P1443 - EVAP CONTROL SYSTEM PURGE CONTROL VALVE NO. 2 CIRCUIT MALFUNCTION
- DTC P1500 - GENERATOR FR TERMINAL CIRCUIT MALFUNCTION
- DTC P1715 - PG ASSEMBLY MALFUNCTION
- DTC P1750 - SOLENOID ASSEMBLY MALFUNCTION
- Engine Controls - System/component Tests - 2.0L Non-Turbo: Diagnosis
- Engine Controls - System/component Tests - 2.0L Non-Turbo: Other
- Engine Controls - Tests W/codes - 2.0L Non-Turbo: Overview
- Engine Controls - Tests W/codes - 2.0L Non-Turbo: Diagnosis
- Engine Controls - Tests W/codes - 2.0L Non-Turbo: Component Locations
- Engine Controls - Tests W/codes - 2.0L Non-Turbo: Other
- Engine Controls - System/component Tests - 2.4L 4-CYL: Diagnosis
- Engine Controls - System/component Tests - 2.4L 4-CYL: Other
- Engine Controls - Basic Testing - 2.0L Turbo: Diagnosis
- Engine Controls - Basic Testing - 2.0L Turbo: Other
- Engine Controls - Tests W/o Codes - 2.0L Turbo: Diagnosis
- Engine Controls - Tests W/o Codes - 2.0L Turbo: Other
- Engine Controls - Basic Testing - 2.0L Non Turbo: Diagnosis
- Engine Controls - Basic Testing - 2.0L Non Turbo: Other
- Engine Controls - Tests W/o Codes - 2.0L Non-Turbo: Diagnosis
- Engine Controls - Tests W/o Codes - 2.0L Non-Turbo: Other
- Engine Controls - Basic Testing - 2.4L 4-CYL: Diagnosis
- Engine Controls - Basic Testing - 2.4L 4-CYL: Other
- Engine Controls - Tests W/o Codes - 2.4L 4-CYL: Diagnosis
- Engine Controls - Tests W/o Codes - 2.4L 4-CYL: Other
- Engine Controls - Tests W/codes - 2.4L 4-CYL: Overview
- Engine Controls - Tests W/codes - 2.4L 4-CYL: Diagnosis
- Engine Controls - Tests W/codes - 2.4L 4-CYL: Component Locations
- Engine Controls - Tests W/codes - 2.4L 4-CYL: Other
- DTC P0100 - VOLUME AIRFLOW (VAF) CIRCUIT MALFUNCTION
- DTC P0105 - BAROMETRIC PRESSURE CIRCUIT MALFUNCTION
- DTC P0110 - INTAKE AIR TEMPERATURE (IAT) CIRCUIT MALFUNCTION
- DTC P0115 - ENGINE COOLANT TEMP (ECT) CIRCUIT MALFUNCTION
- DTC P0120 - THROTTLE POSITION (TP) CIRCUIT MALFUNCTION
- DTC P0125 - EXCESSIVE TIME TO ENTER CLOSED LOOP FUEL CONTROL
- DTC P0130 - FRONT HO2S CIRCUIT MALFUNCTION
- DTC P0135 - FRONT HO2S HEATER CIRCUIT MALFUNCTION
- DTC P0136 - REAR HO2S CIRCUIT MALFUNCTION
- DTC P0141 - REAR HO2S HEATER CIRCUIT MALFUNCTION
- DTC P0170 - FUEL TRIM MALFUNCTION
- DTC P0201, P0202, P0203 OR P0204 - INJECTOR NO. 1, 2, 3 OR 4 CIRCUIT MALFUNCTION
- DTC P0300 - RANDOM MISFIRE DETECTED
- DTC P0301, P0302, P0303, OR P0304 - CYLINDER NO. 1, 2, 3 OR 4 MISFIRE DETECTED
- DTC P0325 - KNOCK SENSOR (KS) NO. 1 CIRCUIT
- DTC P0335 - CKP SENSOR CIRCUIT MALFUNCTION
- DTC P0340 - CMP SENSOR CIRCUIT MALFUNCTION
- DTC P0400 - EXHAUST GAS RECIRCULATION (EGR) FLOW MALFUNCTION
- DTC P0403 - EXHAUST GAS RECIRCULATION (EGR) FLOW MALFUNCTION
- DTC P0420 - CATALYTIC CONVERTER EFFICIENCY BELOW THRESHOLD
- DTC P0421 - WARM-UP CATALYTIC CONVERTER EFFIC BELOW THRESHOLD
- DTC P0440 - EVAPORATIVE (EVAP) CONTROL SYSTEM MALFUNCTION
- DTC P0442 - EVAPORATIVE (EVAP) CONTROL SYSTEM LEAK DETECTED
- DTC P0443 - EVAP CONTROL SYSTEM PURGE CONTROL VALVE CIRCUIT MALFUNCTION
- DTC P0446 - EVAP CONTROL SYSTEM VENT CONTROL MALFUNCTION
- DTC P0500 - VEHICLE SPEED SENSOR (VSS) MALFUNCTION
- DTC P0505 - IDLE CONTROL SYSTEM MALFUNCTION
- DTC P0510 - CLOSED TP SWITCH MALFUNCTION
- DTC P0705 - TRANSMISSION RANGE SENSOR CKT MALFUNCTION (A/T)
- DTC P0710 - TRANSMISSION FLUID TEMP SENSOR CKT MALF (A/T)
- DTC P1105 - FUEL PRESSURE SOLENOID MALFUNCTION
- DTC P1300 - IGNITION TIMING ADJUSTMENT CIRCUIT MALFUNCTION
- DTC P1400 - MDP SENSOR CIRCUIT MALFUNCTION
- DTC P1443 - EVAP CONTROL SYSTEM PURGE CONTROL VALVE NO. 2 CIRCUIT MALFUNCTION
- DTC P1500 - GENERATOR FR TERMINAL CIRCUIT MALFUNCTION
- DTC P1715 - PG ASSEMBLY MALFUNCTION
- DTC P1750 - SOLENOID ASSEMBLY MALFUNCTION
- Abbreviations
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