I own a 95 E320 Coupe with 100K miles.

So far, I changed the head gasket, main electrical harness, mass air sensor, sparks, wires, cables, main fan belt, cat converter, air and fuel filter...

Check engine light is on, the idle studders if in drive or park, I had the car stall on me in the middle of the road and not want to start. There are times I would stop at an atm, walk back to the car and not be able to start it...

I was told by a generic pc these codes: egr and isc.

What should I do next? Should I change EGR valve or could it be a vacuum clog? ISC needs a new M16 motor? P.S. no traction control option on this car, unfortunately.