I have a 1989 560 SEL. The car is running really rough. It really shows up if car is stopped for a red light or traffic. I'm afraid she'll leave me in traffic. It says in the owners manual that if the car runs rough (shaking) at lights or low speed (TRAFFIC FOR ME) it's the oxygen sensor. I also spoke with a mechanic and said there might be an air leak somewhere. How would I go about checking for an air leak? WD-40? And where is the oxygen sensor locates ( I know it's in the pipe, but where?)
TIA,
Bill