Severity: Moderate
Drivable, but it can cause more damage or poor economy. Get it checked within days.
What P0402 means
More EGR flow than expected, often a valve stuck open.
Symptoms
- Rough idle
- Stalling
- Hesitation
Common causes
Most likely first
- 1EGR valve stuck open
- 2Position sensor fault
How we diagnose it
- Command closed and inspect
- Check sensor
Every vehicle sets codes under its own conditions. We check the factory diagnostic steps and service bulletins for your VIN, so the repair targets the actual cause.