I too replaced my fuel filter and pump before replaceing my CPS to fix my on off engine.

I'd bet a 6 pack you can fix it fast.
you need a good torx socket - i bought mine at NAPA.
$60 +- for the part and I have been rolling for many many months.

there are two listed for My ML320, I just remember 1st I ordered the more expensive one and it didnt fit, the cheaper one fit.

__________________
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