600SL ASR Problem

I have reviewed a couple good threads here re similar problem, that is intermittent ASR and limp-home mode, in this case in my 1994 600SL. Here an independent mech 1st pulled only DTC 030. On reset, worked for 24 hours, then steadily became more frequent. Local dealer says DTC 030 plus 224 NEA. I cant find anything re DTC 224. Anyway, I pick up car tonight from dealer with two new throttle actuators. I am told to drive for a week to see if problem fixed - if not, no charge for throtle actuators. Does this make sense? I doubt this dealer did any of the tests I see discussed at ALLDATADIY.com.
Any suggestions?