You may want to try a simple test yourself..if so inclined.

There is a vac line that goes to the EGR and if you take that line off and pull a vac on the egr with a hand pump at idle , the engine should sputter , run rough ,and almost stall.. If it doesn't , then you know the tube is blocked.
[ infamous problem on 104] .. but if it does , then the suspect is that vac is not getting to the egr and on a 104 that is usually just a broken white plastic vac line that runs across the front of the engine [ under that front plastic cover]..notorious fault b/c they crack from heat fatique and then the EGR can not open b/c of no vac, thus setting the code.
The simple fix for that is to just to replace that plastic line with a generic rubber one.....a $2 DIYer fix.

Something to check before going intp the Hospital for Surgury..

__________________
A Dalton