P0404: Exhaust Gas Recirculation Circuit Range/Performance
Can you still drive? Yes, but expect rough running and possible stalling. Have the issue repaired soon to avoid catalyst damage.
What Does P0404 Mean?
Code P0404 means the EGR valve position or flow is outside the expected range during operation. The ECM commands the EGR valve to a specific position, but the feedback sensor reports a value that does not match. This usually indicates a stuck or sluggish EGR valve that is not responding correctly to commands.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Carbon buildup restricting EGR valve movement
- Faulty EGR valve position sensor
- Worn EGR valve pintle or seat
- Vacuum leak in EGR system
- Sticking EGR valve actuator
Symptoms
- Check engine light on
- Rough idle
- Hesitation during acceleration
- Engine stalling
- Failed emissions test
Diagnostic Steps
- 1Monitor EGR valve position with a scan tool while commanding it open and closed
- 2Remove the EGR valve and inspect for carbon buildup
- 3Check the EGR position sensor output against specifications
- 4Verify vacuum supply to the EGR valve if vacuum-operated
- 5Clean the EGR valve and passages, then retest
- 6Replace the EGR valve if cleaning does not resolve the fault
Recommended Parts & Tools
throttle body cleaner
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $100 - $400 |
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Chat with AI About P0404Commonly Affected Vehicles
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Frequently Asked Questions
What causes P0404 most often?
The most common cause is carbon buildup on the EGR valve, which prevents it from moving smoothly to the commanded position. Regular cleaning can prevent this issue.
Can I clean the EGR valve myself?
Yes. Removing the EGR valve and cleaning it with carburetor or throttle body cleaner is a common DIY repair. Make sure to also clean the passages in the intake manifold.
Community Fix Reports
Community reports are user-submitted and not verified by Auto AI Buddy. Results may vary.
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