My wife's 1992 300E just went through this same "SSS". It would stall in stop and go traffic as well as when she was taking a turn a little sharp at an intersection.
I replaced the Overload Protection Relay ($63) which is located behind the battery next to the computer module. It was a 5 minute repair and the problem is now remedied. The old one had water in it which was evidenced by condensation built up under the clear plastic double-fuse cover on same. This is a common problem. When/If you replace the module, put a bit of vaseline on the O-ring gasket for the double-fuse cover. Search the Parts icon on this website for a photo and ording information of this module.
It might also be:
Coil
Fuel Injectors
Wiring harness

But I'd begin with the least expensive and easiest remedy in your troubleshooting and go on from there.

Good luck. Ain't this fun? The Mercedes Benz dealer/service shop in Naples estimated $1400 to do this job for me. They said "wiring harness cracked and needs replacing". Bulls#$& !! There was nothing wrong with the harness. It is brand new and was replaced only 2 years ago. It is in perfect condition.
Watch out for scheisters.