P0404: Exhaust Gas Recirculation Control Circuit Range/Performance
Moderate SeveritySafe to drive (short-term)Emissions
P0404 means the EGR valve is responding to ECU commands, but not within the expected position range. The ECU asks for a specific opening (say 30%) and the position sensor reports something different. Carbon buildup restricting valve travel is by far the most common cause.
Estimated repair costFrom €68 to €1400+, varies by vehicle
What does P0404 mean?
P0404 means the EGR valve is responding to ECU commands, but not within the expected position range. The ECU asks for a specific opening (say 30%) and the position sensor reports something different. Carbon buildup restricting valve travel is by far the most common cause.
P0404 is a emissions-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0404 and illuminates the check engine light.
What are the symptoms of P0404?
If your vehicle has triggered P0404, you may notice one or more of these symptoms:
Check engine light illuminated
Rough idle, especially after warm-up
Hesitation or stumble during light throttle
Slight loss of power and worse fuel economy
Failed emissions or periodic technical inspection
What causes P0404?
Here are the most common causes of P0404, ranked by how likely they are to be the culprit:
highFaulty EGR position sensor reading inaccurate angle
mediumWorn or sticking valve mechanism unable to reach commanded position
mediumWiring or connector resistance affecting sensor signal
lowSoftware calibration issue after ECU reflash (rare)
Is it safe to drive with P0404?
Generally yes, for short-term driving. Driveable. P0404 means the EGR valve is moving, but its actual position does not match what the ECU commanded. Expect rough idle, possible hesitation, and a failed emissions test. Some diesels limit power to protect the DPF and SCR systems.
How do you diagnose P0404?
Follow these steps to pinpoint the root cause of P0404:
Use a scan tool to command the EGR valve through 0%, 25%, 50%, 75%, 100% and watch the position sensor feedback for delay or sticking
Remove the valve and check for carbon buildup at the pintle and seat that limits travel
Inspect the position sensor wiring and connector for corrosion or chafing
Measure position sensor voltage at full closed and full open against the workshop spec
After cleaning or replacement, perform the EGR adaptation procedure if the vehicle requires one (common on BMW, Mercedes, VAG)
How much does P0404 cost to fix?
Repair costs for P0404 vary depending on the root cause and your vehicle. Here are typical estimates:
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Clean EGR valve and recalibrate (where supported)
€8–€25
€60–€180
€68–€205
Moderate
Replace EGR valve (electronic with integrated position sensor)
€150–€450
€80–€220
€230–€670
Moderate
Replace EGR cooler assembly (diesel, when valve is integrated)
€300–€800
€250–€600
€550–€1400
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0404 on specific vehicles
P0404 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:
P0404 on BMW 3 Series
BMW 3 Series • 2007–2024
On the N47 and B47 320d, P0404 typically appears around 100,000–130,000 km as carbon accumulates at the EGR valve seat and limits pintle travel. The position sensor reports the valve isn't reaching commanded angles. Cleaning sometimes works, but on chronically affected engines the EGR cooler-valve assembly is replaced as a unit since they are sold together. EGR adaptation must be reset with INPA, ISTA, or Carly after the job.
What causes P0404 on a BMW 3 Series?
BMW 3 SeriesN47/B47 pintle travel restriction from heavy carbon buildup at valve seat
BMW 3 SeriesEGR cooler-valve sold as one assembly, full replacement required
P0404 repair cost for BMW 3 Series
Estimated costs for BMW 3 Series ownersadjusted higher than average due to BMW-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Clean EGR valve and recalibrate (where supported)
€11–€35
€84–€252
€95–€287
Moderate
Replace EGR valve (electronic with integrated position sensor)
€210–€630
€112–€308
€322–€938
Moderate
Replace EGR cooler assembly (diesel, when valve is integrated)
€420–€1120
€350–€840
€770–€1960
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0404 on Volkswagen Golf
Volkswagen Golf • 2009–2024
EA189 and EA288 Golf TDIs throw P0404 frequently after the Dieselgate update because the new EGR strategy demands wider valve travel. The pintle reaches limit positions where carbon prevents it from closing fully. VCDS can read the position sensor in measured value blocks (group 99 on EA189, group 144 on EA288) to confirm. Adaptation reset via VCDS is required after any valve service.
Volkswagen GolfEA288 position sensor drift, requires VCDS measured value verification
P0404 repair cost for Volkswagen Golf
Estimated costs for Volkswagen Golf ownersadjusted higher than average due to Volkswagen-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Clean EGR valve and recalibrate (where supported)
€9–€29
€69–€207
€78–€236
Moderate
Replace EGR valve (electronic with integrated position sensor)
€173–€518
€92–€253
€265–€770
Moderate
Replace EGR cooler assembly (diesel, when valve is integrated)
€345–€920
€288–€690
€633–€1610
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0404 on Audi A4
Audi A4 • 2008–2024
The A4 2.0 TDI (B8, B9) shares the EA189 and EA288 EGR setup with the Golf, so P0404 has identical root causes. The 3.0 TDI V6 (CCWA, CTBA codes) uses a more complex dual-bank EGR with separate position sensors per bank, and adaptation must be performed for both sides after service. VCDS or ODIS is required.
What causes P0404 on a Audi A4?
Audi A4EA189/EA288 carbon-restricted pintle travel identical to Golf
Audi A43.0 TDI V6 dual-bank adaptation needed after valve service
P0404 repair cost for Audi A4
Estimated costs for Audi A4 ownersadjusted higher than average due to Audi-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Clean EGR valve and recalibrate (where supported)
€10–€31
€75–€225
€85–€256
Moderate
Replace EGR valve (electronic with integrated position sensor)
€188–€563
€100–€275
€288–€838
Moderate
Replace EGR cooler assembly (diesel, when valve is integrated)
€375–€1000
€313–€750
€688–€1750
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0404 on Mercedes Sprinter
Mercedes Sprinter • 2010–2024
OM651 Sprinters often see P0404 alongside P0401 due to heavy commercial duty cycles. The position sensor on the OM651 EGR valve is integrated and not serviceable separately. When the sensor drifts or the pintle sticks, replacement of the complete valve is required, plus Star Diagnosis or XENTRY for the adaptation reset. Skipping the adaptation will cause the code to return.
What causes P0404 on a Mercedes Sprinter?
Mercedes SprinterOM651 integrated position sensor drift, full valve replacement required
Mercedes SprinterMandatory XENTRY adaptation after valve service or code returns
P0404 repair cost for Mercedes Sprinter
Estimated costs for Mercedes Sprinter ownersadjusted higher than average due to Mercedes-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Clean EGR valve and recalibrate (where supported)
€10–€33
€78–€234
€88–€267
Moderate
Replace EGR valve (electronic with integrated position sensor)
€195–€585
€104–€286
€299–€871
Moderate
Replace EGR cooler assembly (diesel, when valve is integrated)
€390–€1040
€325–€780
€715–€1820
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Related diagnostic codes
These codes are often seen alongside P0404 or indicate related issues:
P0403 is a pure electrical circuit fault (open, short, no response). P0404 means the circuit works, but the valve position does not match the commanded position. P0404 is almost always mechanical (carbon buildup, sticking pintle), while P0403 is usually electrical (solenoid, wiring, connector).
Can I drive with P0404?
Yes, short-term. Some modern diesels go into limp mode if the EGR cannot reach commanded positions, because the after-treatment calibration relies on EGR for NOx control. Plan the repair within a few weeks to avoid secondary DPF or SCR codes.
Will cleaning fix P0404 long-term?
On petrol engines, often yes if you also clean the intake manifold passages. On diesels with heavy soot output (BMW N47/B47, VAG EA189), cleaning may only last 20,000–40,000 km before the code returns. If the EGR cooler is degraded, replacement of the cooler-valve assembly is more durable.
Do I need to reset the EGR adaptation after replacing the valve?
Yes on most modern vehicles. BMW, Mercedes, and VAG all use stored adaptation values that must be reset and re-learned after a new EGR valve is fitted. INPA, VCDS, or a similar bi-directional scan tool is required. Skipping this step often causes the new valve to throw P0404 again within a few drive cycles.
