What P0402 means
More exhaust is recirculating than commanded, typically because the valve is stuck open or leaking.
Common causes
- EGR valve stuck open by carbon
- Failed vacuum control solenoid
- Leaking EGR gasket
How it is usually fixed
- 1Clean or replace the EGR valve
- 2Check the control solenoid and vacuum lines
- 3Replace the gasket
Other common codes
- P0011 — Camshaft Position A – Timing Over-Advanced (Bank 1)
- P0030 — HO2S Heater Control Circuit (Bank 1, Sensor 1)
- P0101 — Mass Air Flow Circuit Range/Performance
- P0113 — Intake Air Temperature Sensor Circuit High
- P0118 — Engine Coolant Temperature Sensor Circuit High
- P0131 — O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)
Code information is general guidance, not a diagnosis for a specific vehicle. Confirm with live data and manufacturer test procedures before replacing parts.