Hi Guys,

I just got my 2003 CL55 AMG (C215) and I'm just starting to work on it. The car has this acceleration issue with bogging down under load. It will cruise fine and light throttle is smooth, then after about 20-30% throttle the engine starts misfiring. The car has new plugs and coil packs, so I thought it would be the fuel filter. Then I notice that the arrow stamped on the fuel filter is pointing to the rear of the car... I'm assuming this is how it comes from the factory?

At any rate, I have replaced the fuel filter and ABC, ABS, and ESP messages come up and the CEL is on and is on safety mode.

Did I install the fuel filter incorrectly? or what???

Also, the fuel filter part number is different on the car and one that dealership gave me... but look identical.

My OBD2 scanner just took a crap, so I need to get a new one... help me out please!

Got a new scanner... P0303... but only comes on at moderate to full throttle.

Once you clear the code, the car runs fine, as long as it's under light throttle.

Throttle pedal, possibly. You can google how to test throttle pedal pontentiometers, it's a pretty similar process for all vehicles. also try changing the cylinder 3 pack and cables with old ones. The arrow indicates fuel flow direction, out the direction the arrow points.