P0404 Code: Exhaust Gas Recirculation (EGR) Circuit Range/Performance
🟠 Moderate severity · drivable
Drivable, but the EGR valve isn't responding correctly, which can affect idle and emissions.
What P0404 means
The EGR valve's position sensor is reporting a reading that doesn't match what the computer commanded. In other words, the EGR valve isn't opening or closing the way it should.
Symptoms
- Check engine light is on
- Rough or unstable idle
- Possible stalling
- Possible pinging under load
Common causes
- most common: Faulty EGR valve or its position sensor
- common: Carbon buildup restricting EGR valve movement
- less common: Wiring or connector problem at the EGR valve
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Clean carbon from the EGR valve so it moves freely | Yes | $20–100 |
| Replace the EGR valve | Yes | $100–400 |
| Inspect and repair the EGR wiring and connector | Mechanic | $50–150 |
Frequently asked questions
Can I drive with a P0404 code?
Yes for a short time. The EGR valve isn't working correctly, which can cause rough idle and failed emissions tests.
What is the most common cause of P0404?
A faulty EGR valve or carbon buildup preventing it from moving. Cleaning or replacing the valve usually fixes it.
How much does it cost to fix a P0404?
Typically $100–$400 for a new EGR valve, or $20–$100 if cleaning resolves it.
Related codes
P0401
P0401 Code: Exhaust Gas Recirculation (EGR) Flow Insufficient Detected
P0400P0400 Code: Exhaust Gas Recirculation (EGR) Flow Malfunction
P0403P0403 Code: Exhaust Gas Recirculation (EGR) Circuit Malfunction
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.