Your car likely has the 4G15 or perhaps the 4G93.

Your "friend" needs to start with the basics, and for the moment ignore the
error code that suggests the EGR system. Shakes are caused by many things,
which he should know.
a) bad plug leads, old plugs : replace
b) tight tappets - readjust
c) injectors are gummed up : take out and soak in injector cleaner.
d) vacuum leaks : look for leaks, replace the little hoses.
e) adjust the idle speed and timing.

Replacing the EGR valve is usually not the problem: a build up of oily
carbon in the EGR system is blocking the operation. If the build up is not
cleaned out, replacing the EGR valve is a waste of money. The build up is
caused by valve stem seal wear (very common at 180,000km+) and sometimes
piston rings.

Other issues, related to emissions stuff, which may actually be the problem
f) O2 sensor(s) may need replacing, but these usually won't cause the
shakes.
g) fuel filter could be partially blocked.
h) catalytic converter could (and probably does for a 95) need replacing.

What this boils down to is the engine needs a thorough, possibly major (ie
head reconditioning), service. Get the above looked at and then decide if
its worth keeping the car.