P0404 on Mitsubishi
Exhaust Gas Recirculation Circuit Range/Performance
P0404 on Mitsubishi vehicles indicates exhaust gas recirculation circuit range/performance. Au7o has documented this code across 1 Mitsubishi model — most commonly on Outlander. This code means the exhaust gas recirculation (EGR) system isn't performing within its expected range. The EGR valve routes a metered amount of exhaust gas back into the intake to lower combustion temperatures and reduce nitrogen-oxide emissions, and the computer monitors the valve's actual position versus what it commanded. When the valve sticks, moves incorrectly, or the feedback doesn't match the command, P0404 sets. This can cause rough idle, hesitation, pinging, and increased emissions.
Common Causes of P0404
- •Carbon buildup clogging the EGR valve or passages
- •Sticking or failed EGR valve
- •Faulty EGR position sensor
- •Corroded or loose EGR connector
- •Damaged or shorted EGR wiring
- •Vacuum leak or failed vacuum control (on vacuum-operated systems)
- •Clogged EGR cooler or tubes
- •Faulty PCM/ECM (rare)
P0404 on Mitsubishi by Model
Mitsubishi Outlander(1 issue)
- Engine Malfunction / 'Power Reduced' Warning from ECU Software (False P0401/P0404, TSB-22-13-001)2022
Early 2022 Outlanders with the 2.5L engine can illuminate the check-engine light and display an 'Engine malfunction / Power reduced — service now' message while idling or driving, often storing EGR-related codes (P0401/P0404) that do not reflect an actual hardware fault. Mitsubishi traced this to engine-ECU control software and issued TSB-22-13-001 to reflash the ECU with countermeasure software on vehicles built before December 16, 2021.
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View P0404 across all makes →Frequently Asked Questions
What does P0404 mean on Mitsubishi?▼
P0404 stands for "Exhaust Gas Recirculation Circuit Range/Performance." This code means the exhaust gas recirculation (EGR) system isn't performing within its expected range. The EGR valve routes a metered amount of exhaust gas back into the intake to lower combustion temperatures and reduce nitrogen-oxide emissions, and the computer monitors the valve's actual position versus what it commanded. When the valve sticks, moves incorrectly, or the feedback doesn't match the command, P0404 sets. This can cause rough idle, hesitation, pinging, and increased emissions. On Mitsubishi specifically, this code is documented across 1 model.
What causes P0404 on Mitsubishi vehicles?▼
Common causes on Mitsubishi: Carbon buildup clogging the EGR valve or passages, Sticking or failed EGR valve, Faulty EGR position sensor, Corroded or loose EGR connector, Damaged or shorted EGR wiring. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0404 on a Mitsubishi?▼
Repair costs vary widely depending on the root cause and specific Mitsubishi model.
Which Mitsubishi models have P0404 documented?▼
Au7o has documented P0404 on 1 Mitsubishi model: Outlander.