Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1998 Mitsubishi MonteroFACTORY OEM SERVICE PROCEDURE
Engine Controls - Tests W/Codes
- Introduction
- Self-Diagnostic System
- Trouble Code Definition
- Summary
- Terminal Identification
- Diagnostic Tests
- DTC Tests
- DTC P0100: Volume Airflow (VAF) Sensor Circuit Malfunction
- DTC P0105: Barometric (BARO) Pressure Sensor Circuit Malfunction
- DTC P0110: Intake Air Temperature (IAT) Sensor Circuit Malfunction
- DTC P0115: Engine Coolant Temperature (ECT) Sensor Malfunction
- DTC P0120: Throttle Position (TP) Sensor Circuit Malfunction
- DTC P0125: Excessive Time To Enter Closed Loop Fuel Control (Except 3.0L With CALIFORNIA Emissions)
- DTC P0125: Excessive Time To Enter Closed Loop Fuel Control (3.0L With CALIFORNIA Emissions)
- DTC P0130: Front Heated Oxygen Sensor (Ho2S) Circuit Malfunction (2.4L)
- DTC P0130: Front Heated Oxygen Sensor (Ho2S) Circuit Malfunction (3.0L)
- DTC P0135: Front Heated Oxygen Sensor (Ho2S) Heater Circuit Malfunction (2.4L)
- DTC P0135: Front Heated Oxygen Sensor (Ho2S) Heater Circuit Malfunction (3.0L)
- DTC P0136: Rear Heated Oxygen Sensor (Ho2S) Circuit Malfunction (2.4L)
- DTC P0136: Rear Heated Oxygen Sensor (Ho2S) Circuit Malfunction (3.0L)
- DTC P0141: Rear Heated Oxygen Sensor (Ho2S) Heater Circuit Malfunction (2.4L)
- DTC P0141: Rear Heated Oxygen Sensor (Ho2S) Heater Circuit Malfunction (3.0L)
- DTC P0150: Left Front Heated Oxygen Sensor (Ho2S) Circuit Malfunction
- DTC P0155: Left Front Heated Oxygen Sensor (Ho2S) Heater Circuit Malfunction
- DTC P0156: Left Rear Heated Oxygen Sensor (Ho2S) Circuit Malfunction
- DTC P0161: Left Rear Heated Oxygen Sensor (Ho2S) Heater Circuit Malfunction
- DTC P0170: Fuel Trim Malfunction
- DTC P0173: Fuel Trim Malfunction
- DTC P0201-P0204: Cylinders No. 1-4 Fuel Injector Circuit Malfunction (2.4L)
- DTC P0201-P0206: Cylinders No. 1-6 Fuel Injector Circuit Malfunction (3.0L)
- DTC P0300: Random Misfire Detected
- DTC P0301-P0306: Cylinders No. 1-6 Misfire Detected
- DTC P0335: Crankshaft Position (CKP) Sensor Circuit Malfunction
- DTC P0340: Camshaft Position (CMP) Sensor Circuit Malfunction
- DTC P0400: Exhaust Gas RECIRCULATION (EGR) Flow Malfunction
- DTC P0403: Exhaust Gas RECIRCULATION (EGR) Solenoid Malfunction
- DTC P0420 (Federal) & DTC P0421 (CALIFORNIA): Catalyst Efficiency Below Threshold
- DTC P0431: Catalyst Efficiency Below Threshold
- DTC P0442: Evaporative (EVAP) Emission Control System Leak Detected
- DTC P0443: Evaporative (EVAP) Emission Control System Purge Control Valve Circuit Malfunction
- DTC P0446: Evaporative (EVAP) Emission Control System Vent Control Malfunction
- DTC P0450: Evaporative (EVAP) Emission Control System Pressure Sensor Malfunction
- DTC P0455: Evaporative (EVAP) Emission Control System Large Leak Detected
- DTC P0500: Vehicle Speed Sensor (VSS) Circuit Malfunction
- DTC P0505: Idle Control System Malfunction (2.4L)
- DTC P0505: Idle Control System Malfunction (3.0L)
- DTC P0510: Closed Throttle Position (TP) Switch Malfunction
- DTC P0551: Power Steering Pressure (PSP) Sensor Circuit Performance
- DTC P0705: Transmission Range Sensor Circuit Malfunction
- DTC P1400: Manifold Differential Pressure (MDP) Sensor Circuit Malfunction
- DTC P1600: Serial Communication Link Malfunction
- DTC P1715: Pulse Generator Malfunction
- DTC P1750: Solenoid Malfunction
- DTC P1791: Engine Coolant Temperature Level Input To TCM
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.