What usually causes it
- An EGR valve stuck open
- A faulty EGR position sensor
- A bad control solenoid or vacuum problem
- Damaged wiring
P0402Starts at: OK to drive, fix when convenient
EGR flow is too high
The EGR system sends a small amount of exhaust back into the engine to keep it cooler and cleaner. More exhaust is flowing than the computer expects.
Check this first
Look at the small rubber hoses on the EGR valve for cracks or loose ends.
What to watch for
- Rough idle or stalling when you slow down
- Hesitation when you press the gas
- Poor gas mileage
Can I keep driving?
We rate P0402 as OK to drive, fix when convenient, as a starting point. Keep an eye on the signs below. If the light starts flashing, stop driving soon.
Quick answers about P0402
What does P0402 mean?
EGR flow is too high. The EGR system sends a small amount of exhaust back into the engine to keep it cooler and cleaner. More exhaust is flowing than the computer expects.
Can I keep driving with P0402?
We rate P0402 as OK to drive, fix when convenient, as a starting point. Keep an eye on the signs below. If the light starts flashing, stop driving soon.
What usually causes P0402?
The most common causes, in order: An EGR valve stuck open; A faulty EGR position sensor; A bad control solenoid or vacuum problem; Damaged wiring.
Estimates only. A mechanic should confirm. The same code can mean slightly different things on different cars; the app explains it for your exact year, make, model and mileage.