Air Mass Meter (CFGB) - Implausible Reading

Hi,
A Passat has recently started exhibiting issues with excessively high measured air masses (see Autoscan). The error likely first appeared about a week ago while driving in the mountains. The ADAC (German automobile club) read the error codes but did not clear them. Two days later, the DPF (Diesel Particulate Filter) warning light came on, and the filter was "regenerated" through a cleaning cycle.
The DPF light then also turned off.
nach ca 800 km Fahrt am WE entstand dann der Autoscan. Fehler wurden gelöscht und auch die Readiness war wieder ok (lt. Advertisement in VCDS.
Today, the same error reappeared. The DPF light came on. The error was cleared, but the DPF light remains on (presumably due to excessive soot buildup).
Readiness indicates an "Exhaust Gas Recirculation (EGR) error," but no error is currently displayed in the system.

Could it be that the EGR valve is no longer opening correctly, since the mass airflow sensor is measuring too much air, indicating an obvious deficiency in the amount of exhaust gas being recirculated? The error with the mass airflow sensor seems to only occur (twice) when the EGR valve is at 100% activation, meaning fully open (or am I interpreting that incorrectly?)

Okay... the DPF ash loading is indicated as 220 ml, so a cleaning procedure is probably needed.

Best regards from Berlin.
olli

Hello,

I suspect either the AGR valve is not opening correctly, or the AGR pipes are so heavily carbonized that their cross-section is reduced, preventing sufficient exhaust gases from being drawn in.

Best regards, Rainer.