Gyri

Hi, does my w124 E220, 96 (petrol) have an EGR valve? (pardon my ignorance). If it does, where is it located? The usual problem that plagues most W124s has been bothering me as well, engine stalling while coasting to a stop light, rpm hunting between 500 and 900, quarter second hesitation when stepping on accelerator after shifting gears. Had the car looked into by the Merc "specialist" (the authorised folks) and they went through it for 2 months with no luck or help to me.
We have checked the following (BTW car has done 40,000 KM).
1. OVP relay has been checked ok, it's the newer SIEMENS make.
2. Throttle body has been cleaned, although to begin with it bearly had any dirt.
3. All filters have been changed with all lubrication and coolants are fresh.
4. Got a new fuel pump on, although old pump has been working well, only with loud hissing.
5. Old thottle cable seemed weak and chipped, so had a new one installed.
6. My engine wiring harness was worn out and Mbenz had it re-insulated, not sure if they did a great job, so planning to order a new set, as soon as I can get the correct part no. for it. They have removed the sleeve where the part# is normally printed while re-insulating. I know where my next pay check is going!
7. New spark plugs. Ignition wiring looks good.
8. Injectors were cleaned recently.
From the various posts in this forum I figured somewhere that someone with similar problem squirted Wd-40 on to the piston in the EGR and got the problem sorted out (yup! as simple as that). I am hoping for such luck, as long as my car has an EGR (no laughing at my ignorance).
Also is there someplace that I am not looking into?
Thanks in advance for all your replies.