OBD-II code · Powertrain (generic)
P0402 Exhaust Gas Recirculation Flow Excessive Detected
EGR flow is higher than expected when the valve should be closed, or higher than commanded when partially open. Typically a valve that has stuck open due to carbon, causing rough idle and stalling.
Is it safe to drive with P0402?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyEGR valve stuck open
- PossibleValve seat eroded — does not seal
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 1–5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Egr Valve
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.