OBD-II code guide
P0404 EGR Circuit Range or Performance
P0404 means the EGR position or control signal is not matching what the computer expects.
What it means
The EGR valve may not be moving correctly or the feedback signal may be inaccurate.
Common symptoms
- Check engine light
- Rough idle
- Hesitation
- Pinging
- Failed emissions test
Likely causes
- Sticking EGR valve
- Carbon buildup
- Position sensor fault
- Wiring problem
- Control circuit issue
First checks
- Inspect connectors and wiring.
- Check for carbon buildup around the valve.
- Compare commanded and actual EGR position if the scan tool supports it.
- Look for related P0401 or P0402 codes.