Yes
the TUBE
the EGR valve needs to pass gas from itself thru the EGR TUBE to the rocker cover or intake manifold..I forget.

They should have Cleaned the tube along with the valve, but I dont know.

Outside of that, there are many more gifted mechanic's here than I that may have suggestions.

__________________
Steve Danville
what i did myself.
CPS
rear shocks
MAS x 3.
SparkPlugs (twice)
Fuel pump & Filter
Window switch
replaced both failed horns with Honda horns.
Cleaned ERG Tube
Oil changes
Oil consumption Fix
Brake Pads
A/C Recharge
Anti-Freeze change X 2.
Front Shocks. Monroe. $90
Mercedes Warrenty Work:
Harmonic balancer,power steering clamp. Cat converters.Drive Shaft Bearing.s
Replaced Outer Lower Tie Rods and front lower ball joints at 156,000 miles