I'm a friend of Bryan @ Vintage Benz (he said to say that!) The EGR valve has been checked by Frank @ Franks garage in Lansing. He only does Benz work. EGR valve was cleaned along with pipe. Solenoid is working, EGR is ok, vacuum is good. He zeroed code, but came back. Car bobbles on excelleration intermittently. Don't know what to do next. Any ideas? Frank has the car right now but it's not doing what I experienced. Check engine light back on and same code. ???