P0171 Mercedes-Benz -

Question

My vehicle run very smooth but sometimes the engine shake.

Answer 1

P0171 Fuel trim lean Bank 1

Check the sparkplug condition, especially for the Kompressor 1.8 oil tends to get into the sparkplug well. There is set a lean misfire condition

 

 Here sparkplug from a Kompressor, This only had a slight hesitation and a lean code condtion. As for MBZ it is very sensitive to valve deposits, to help maintain valve deposit use a fuel injector cleaner that is added to the fuel tank , use it at every oil change or every full tank