Exhaust Gas Recirculation Circuit Range/Performance
The P0404 code means the vehicle's onboard diagnostic system has detected: Exhaust Gas Recirculation Circuit Range/Performance. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $100 - $400 (parts and labor)
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Common Symptoms
- Check Engine Light illuminated
- Rough or fluctuating idle
- Hesitation during acceleration
- Engine stalling at stops
- Failed emissions test
Probable Causes (Ranked by Likelihood)
- Carbon buildup restricting EGR valve movement Very High
- Faulty EGR valve position sensor High
- EGR valve pintle sticking intermittently Moderate
- Incorrect EGR valve installed after replacement Low
Common Fixes by Vehicle
What techs usually find when diagnosing P0404 on specific vehicles — tap your vehicle for the fix and the exact part:
2004-2012 Chevrolet Colorado/GMC Canyon 3.5L/3.7L Moderate DIY
The EGR valve position sensor reads out of range due to carbon deposits on the pintle. Remove the EGR valve (two bolts), clean the pintle and seat with throttle body cleaner, and reinstall with a new gasket. If cleaning does not fix it, replace with an OE-quality ACDelco unit. Confirm the exact part for your year and engine with a retailer's fitment lookup or your VIN before ordering - these applications split by engine and build date.
Labor: 1-1.5 hours2003-2011 Ford Crown Victoria 4.6L Easy DIY
DPFE sensor failures cause false EGR position readings on Ford 4.6L modular engines. Replace the DPFE sensor first (Motorcraft) before condemning the EGR valve. The sensor is on the firewall connected by two small rubber hoses to the EGR tube. Confirm the exact part for your year and engine with a retailer's fitment lookup or your VIN before ordering - these applications split by engine and build date.
Labor: 15-30 minutes2003-2009 Honda Accord 2.4L K24 Easy DIY
The EGR valve position sensor drifts out of calibration on high-mileage K24 engines. Clean the EGR valve with carb cleaner first and check if the code clears. If it returns, the valve needs replacement. Use a genuine Honda or Dorman aftermarket unit. Confirm the exact part for your year and engine with a retailer's fitment lookup or your VIN before ordering - these applications split by engine and build date.
Labor: 0.5-1 hourFrequently Asked Questions
Can I drive with code P0404?
You can drive short distances. The EGR valve is not responding as expected, which can cause rough idle or stalling. If the engine runs rough, avoid driving until repaired.
Is P0404 common on GM trucks?
Only on the earliest model years. GM's 4.8L, 5.3L, and 6.0L gas V8 trucks used an EGR valve through roughly the 2002 model year; GM then deleted the EGR valve on these engines (around 2003), so 2003-and-newer gas V8 GM trucks have no EGR valve and cannot set P0404. P0404 shows up on vehicles that kept a conventional electronic EGR valve, where carbon buildup on the valve pintle restricts its commanded movement.
Can cleaning fix P0404?
Often yes. Removing the EGR valve and thoroughly cleaning carbon deposits from the pintle and passages resolves the range/performance issue. Replace the valve only if cleaning does not restore proper operation.
What actually makes the computer set an EGR code?
The OBD II regulation requires the system to flag EGR when flow deviates from the manufacturer's specified rate — in either direction, too much or too little — by enough to push emissions past 1.5 times the FTP standards; and, where no EGR fault could do that, when there is no detectable EGR flow at all (Title 13 CCR 1968.2, section (e)(8.2)). Note that excess flow is a malfunction too, which is why an EGR code does not automatically mean a blocked passage. This is the threshold the monitor is designed around, not a description of your specific fault — the regulation says what the system must detect, not how to find it on your vehicle.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Use a scan tool to command the EGR valve through its full range and monitor position sensor feedback
-
Compare commanded position to actual position -- a deviation greater than 10% indicates a problem
-
Remove the EGR valve and inspect the pintle for carbon buildup restricting movement
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Check EGR position sensor voltage sweep -- should transition smoothly from closed to open
-
Clean the EGR valve and passages, then retest with a scan tool
Sources 3
This page is built from documented references. Verify against your own service info before repair work.
- California Code of Regulations, Title 13 section 1968.2 (OBD II)malfunction criteria, section (e)
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
P0404 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
Commonly Affected Vehicles
- 1999-2002 Chevrolet Silverado / GMC Sierra (gas V8, EGR-equipped years)
- 2000-2005 Chevrolet Impala / Malibu (3.4L V6)
- 2004-2012 Chevrolet Colorado / GMC Canyon
- 2004-2010 Ford F-150 and Explorer (EGR/DPFE)
- Honda Accord and CR-V (EGR-equipped years)
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