Code result
P0402
Exhaust Gas Recirculation Flow Excessive Detected
Moderate severity
What it means
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?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
EGR valve stuck open
highOne of the most commonly reported causes for this code — check this first.
Valve seat eroded — does not seal
mediumA plausible cause — test and verify before replacing parts.
Related help
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