P0404 on Mercedes-Benz
Exhaust Gas Recirculation Circuit Range/Performance
P0404 on Mercedes-Benz vehicles indicates exhaust gas recirculation circuit range/performance. Au7o has documented this code across 1 Mercedes-Benz model — most commonly on Sprinter. 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. Typical repair costs on Mercedes-Benz range from $550 to $1,900, depending on the specific model and root cause.
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 Mercedes-Benz by Model
Mercedes-Benz Sprinter(1 issue)
- EGR Valve and EGR Cooler Carbon Clogging (Limp Mode, P0400-Series Codes)2007-2020
Sprinter diesels (OM642 V6 and OM651 4-cylinder) recirculate soot-laden exhaust through the EGR valve and cooler. Over tens of thousands of miles the valve and the cooler's small passages choke with hard carbon, causing the valve to stick, EGR flow to read out of range, rough running, power loss and limp mode. Short-trip/urban duty cycles accelerate the buildup. The cooler is often more clogged than the valve and frequently cannot be cleaned, requiring replacement.
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View P0404 across all makes →Frequently Asked Questions
What does P0404 mean on Mercedes-Benz?▼
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 Mercedes-Benz specifically, this code is documented across 1 model.
What causes P0404 on Mercedes-Benz vehicles?▼
Common causes on Mercedes-Benz: 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 Mercedes-Benz?▼
Repair costs on Mercedes-Benz range from $550 to $1,900, depending on the specific model and root cause.
Which Mercedes-Benz models have P0404 documented?▼
Au7o has documented P0404 on 1 Mercedes-Benz model: Sprinter.