The EGR on that model is at the end of the exhaust manifold.
The easy test is to apply vac [ with a hand pump] to the small inlet of the valve while the car is at idle.
If the car run rough when the vac opens the egr and the egr snaps shut when you release the vac., the egr is suspect of sticking .
If the valve opens and no change in idle, the pipe at the intake from the valve is plugged [ common on 104 eng]
* see archieve DIY article by SB.