Yellow warning light.

[No1Cman]

Am currently driving E class 200 kompressor w211 but have experienced difficulty in last 3 weeks with the yellow warning light.Diagnostic read too problem with mix code p0171 therefore problem with oxygen lambda sensor which I replaced and also replaced air filter and 4 new spark plugs.Car was still guzzling fuel and light on.Then second diagnostic read engine misfire 0401 /0404 with coil packs 1 and 4 also replaced and 0171 back on again despite new sensor.Light has come back on still reading 0171 Any thoughts on this?? Many thanks

 

[Giantvanman]

Those codes on here http://www.mbclub.co.uk/forums/engine/167900-full-diagnostic-trouble-codes-list.html are:-
"P0171 System too Lean (Bank 1)"
"P0401 Exhaust Gas Recirculation Flow Insufficient Detected" and
"P0404 Exhaust Gas Recirculation Control Circuit Range/Performance"

There seems to be a disparity with the codes from "our" list and your readings.

 

[No1Cman]

Apologies it should have read p0301/ p0304 engine misfire detected.Coil packs replaced yellow light still showing and still reading P0171 System too Lean (Bank 1)" very frustrating..

 

[clk200komp]

http://www.mbclub.co.uk/forums/engine/179778-more-codes-me-advice-please-2.html