2001 Mercedes Benz E430 engine code

P0170: Self adaptation of idle mixture formation, right cylinder bank, to limit value of ME-SFI

P0173: Self adaptation of idle mixture formation, left cylinder bank, to limit value of ME-SFI

Your vehicle is running outside of the air fuel mixture limits of your vehicle fuel injection control module. This is more than likely causing a rich running condition. This can be caused by several components being faulty including your fuel pressure regulator, fuel injectors, MAF sensor just to name a few.