DTC P0402: EGR "A" Flow Excessive Detected
WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
For the diagnostic procedure and detection standard, refer to DTC P0401. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0401 EGR ABNORMAL (EGR AMOUNT TOO SMALL)