Mercedes EGR valve problem.

This is a 2004 Mercedes E320 which had code P0400 of EGR valve flow. The problem was not the valve itself, but the hose that supplies vacuum to the valve.

[@Godistheway4519]

Where is the EGR on the cls 550 Mercedes

[@haramaschabrasir8662]

550 is a different engine. Shown here is the M112/113 engine from the E320 or E500. The E350 and CLS350 and 550 have a different engine.