RE: my 1995 E320. I got code #5 - EGR issues. I replaced the EGR valve (existing one was original and falling apart), I cleaned out the EGR tube with a speedometer cable and drill, I blew the carbon out the other detached end of the tube. I even replaced the intake air sensor (cheap money - one less thing to worry about). I STILL have a code #5 EGR system. What could be left that's causing this?