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P0402: Exhaust Gas Recirculation Flow Excessive Detected
Severity: Medium Drive gently and get it diagnosed soon.
What does P0402 mean?
The computer sees more EGR flow than it commanded, often from a valve stuck open.
Generic OBD-II definition: Exhaust Gas Recirculation Flow Excessive Detected. Confirm applicability in your vehicle service information.
Common causes
- Carbon-clogged EGR passages
- Stuck or faulty EGR valve
- Faulty EGR position sensor or DPFE sensor
- Cracked vacuum lines (older vehicles)
Symptoms
- Rough idle
- Stalling at idle
- Hesitation
Can I keep driving with P0402?
Severity: Medium Drive gently and get it diagnosed soon.
If the check engine light is flashing or the car runs badly, stop driving and have it checked.
Typical fixes
- Inspect EGR valve for sticking open
- Clean or replace valve