P0404 on BMW
Exhaust Gas Recirculation Circuit Range/Performance
P0404 on BMW vehicles indicates exhaust gas recirculation circuit range/performance. Au7o has documented this code across 3 BMW models — most commonly on 8 Series, M3, X5 M. 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 BMW range from $150 to $5,500, 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 BMW by Model
BMW 8 Series(1 issue)
- Premature Tire Wear (All 8 Series & M8)2019-2024
All 8 Series and M8 models experience premature tire wear, particularly on the rear tires, due to aggressive factory alignment settings. The rear suspension uses approximately -2.0 degrees of negative camber from the factory, which causes rapid inner edge tire wear. Rear tires commonly need replacement at only 9,000-15,000 miles instead of the typical 25,000-40,000 miles for performance tires. The aggressive camber is set for handling performance but is excessive for street driving and dramatically shortens tire life. Reducing rear camber to approximately -1.5 degrees through a performance alignment ($150-300) significantly extends tire life while maintaining good handling characteristics for street use. Staggered tire setup (wider rear than front) means rear tires cannot be rotated to front, compounding the wear issue. M8 Competition with its even wider rear tires is most affected.
BMW M3(1 issue)
- G80 Integrated Brake System Weld Defect2021-2022
Certain 2021 BMW M3 G80 models were affected by a recall (NHTSA 21V-062) due to improper welding within the integrated brake system. The rotor and shaft may not have been welded properly and could separate during hard braking, potentially causing loss of ABS and braking assistance.
BMW X5 M(1 issue)
- Rear Differential Wear & Fluid Degradation - E70/F85/F95 X5 M2010-2023
The X5 M rear differential handles massive torque loads from the S63 V8 through the xDrive system. The factory differential fluid degrades faster than BMW's "lifetime fill" claim suggests, especially under spirited driving or track use. Degraded fluid causes increased friction, heat, and accelerated gear wear. The E70 X5 M differential has no drain plug, requiring fluid extraction through the fill port with a hand pump or suction device - a design that discourages regular fluid changes. The limited-slip differential internals (clutch packs) wear over time, reducing the diff's ability to transfer torque to the wheel with traction. XBimmers forum reports differential vibration and noise developing after 80,000 miles on vehicles with original fluid. Royal Purple 75W-140 GL5 synthetic is the community-preferred replacement fluid for reduced operating temperature and improved protection.
Looking for P0404 on a different make?
View P0404 across all makes →Frequently Asked Questions
What does P0404 mean on BMW?▼
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 BMW specifically, this code is documented across 3 models.
What causes P0404 on BMW vehicles?▼
Common causes on BMW: 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 BMW?▼
Repair costs on BMW range from $150 to $5,500, depending on the specific model and root cause.
Which BMW models have P0404 documented?▼
Au7o has documented P0404 on 3 BMW models: 8 Series, M3, X5 M.