s550hollywood

I cannot get to the front left upstream Oxygen sensor on driver side as the space is to too tight to reach hand in. Have you ever done this job before and if so did you take the exhaust down to do it or how is it typically done without removing the engine or exhaust? I was able to replace the left front downstream and upstream and downstream on passenger side. Now I have 3 new ones and 1 old.


Heres the problem one circled in red right in front of the driver seat next to the steering column. Its easily seen but no hand can reach it. I was able to get a 22mm crows foot wrench on it to loosen it but I cannot get to it from top or below by hand. Also the electrical plug to it is out of reach.


2013 Mercedes S550 M278 Engine W221