jmedeiros40

Good evening,
My wife has a 2008 R350 4matic with 162,500 miles one of the coils went and I replaced all of the coils and plugs car was back to normal running beautifully cleared the codes and drove it for a couple of days when the engine light came back on crazy thing is the car is idling and running perfectly, I apologize I should have the codes but wasn't planning on jumping on here, basically its telling me the left bank is running lean. I don't have a clue as to what to check or change so I guess what I am asking for are the possibles. MAF sensor seems to be okay....per benz mechanic what else could it be? Any ideas are greatly appreciated, car needs to get inspected asap.

Thank you for reading my post.

nota_amg

Have you checked/replaced the up-stream O2 sensors? Misfires can burn them up sometimes...If they've not been replaced, with your mileage, I'd start there.
Also could be an intake leak from a bad gasket or broken manifold. A smoke machine would be your friend on that one...

efzauner

here you go...
https://www.autocodes.com/p0171_mercedes-benz.html

jmedeiros40

Thank you very much, never thought of the 02 sensors, Praying of the options you've given me its the sensors.

Thanks again, and have a great night.

jmedeiros40

Thank you very much, that is very helpful. Hopefully I can get into it this weekend and get that light out permanently.

Thanks again and have a great night.