Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the car's system that helps control pollution. It's like when a part that helps clean the air isn't working right.
The P0404 code indicates that the Engine Control Module (ECM) has detected a problem with the Exhaust Gas Recirculation (EGR) system's performance.
The EGR system is designed to recirculate a portion of the exhaust gases back into the engine cylinders to reduce nitrogen oxide emissions. The ECM monitors the EGR valve's position and operation. If the EGR valve does not operate within the expected range or performance, the P0404 code is triggered.
• Check Engine Light is on
• Rough idle
• Engine performance issues
• Faulty EGR valve
• EGR valve position sensor malfunction
• Wiring or connector issues in the EGR circuit
EGR: Exhaust Gas Recirculation
ECM: Engine Control Module
• Use an OBD-II scanner to confirm the P0404 code.
• Inspect the EGR valve and its wiring for damage or disconnections.
• Test the EGR valve position sensor for proper operation.
• Replace the faulty EGR valve.
• Repair or replace damaged wiring or connectors.
• Replace the EGR valve position sensor if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regular maintenance of the EGR system.
• Use high-quality fuel to reduce carbon buildup.
• Check and clean EGR passages periodically.
Engine Performance
• Do not ignore the Check Engine Light.
• Have a professional diagnose and repair the issue.
• Regularly maintain the vehicle to prevent recurrence.
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
The P0404 code has been a common issue since the introduction of OBD-II systems in the mid-1990s, often linked to carbon buildup in the EGR system.
Moderate – While the vehicle may still be drivable, it is important to address emissions-related issues promptly to avoid further damage.
Driving with an emissions-related fault can lead to increased pollution and may not pass emissions testing, which is required in some areas.
• Engine at operating temperature
• Vehicle running at various speeds
The EGR valve is typically located on the engine intake manifold.
Q: Can I drive with a P0404 code?
A: While you can drive with this code, it's best to fix it soon to avoid potential engine damage.
Q: What happens if I ignore the P0404 code?
A: Ignoring the code can lead to increased emissions, poor engine performance, and potential engine damage.
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