Damn # 5 code came up again!
 

A couple of days ago, wife tells me check engine light is on again. Looks like the EGR inoperative thingy. Geez, in a diesel, we look to disconnect the damn thing to get more power. Can we disconnect this vale in a '94 E320? Car's running no so smooth as before but not so bad. Should I get my indy to clean out the hot inlet tube? Does he have to take off the intake manifold? Damn that EGR valve is an expensive part- $210! I hope it doesn't need replacing. Had this problem before with other codes but cleared when I replaced the spark plug connectors.

Search back about a half day for discussion on the egr itself.

EGR thread

Has the tube ever been cleaned? My guess is that it's plugged up. The crud typically accumulates at the first few inches from the intake manifold.