Don't assume that the rough idle and P1341 code are related. You could have two separate issues.

The majority of P1341 codes are caused by malfunctioning camshaft advance mechanism's, IMHO. Since they're actuated by by oil pressure, they tend to get "gunked up", especially on higher mileage cars. Of course, there are other things that need to be checked before you replace the timing device, which isn't exactly a DIY job.

Make sure that the camshaft solenoid is connected properly. It's the big round thing on the front of the engine, drivers' side. It only has two wires going to it, but look at them carefully. I've heard that some mid-nineties MB's have had wiring harness issues.