Your EGR essentially reduces the displacement of your engine by bleeding a little exhaust gas back in to the intake. The effect is that the fresh air coming in to the engine is diluted, causing a lower ratio of oxygen to burn. In response, less fuel is added to prevent a rich mixture. On a long trip, this can cause a significant mileage increase. It also reduces the combustion temperature, the desired effect is to reduce harmful emissions caused by high burn temps, but also prevents burning your valves. So having a working EGR system, especially on a long trip, could save you money (fuel) and prevent serious engine damage.

I don't know which system you have specifically, but here are some basic tests. With the engine idling, attach a vacuum pump to the EGR and apply vacuum. The engine should stumble or die. If it doesn't, either the diaphram is ruptured (won't hold vacuum) or the ports are restricted (very common on the 22R. Unfortunately, to clean them out, you need to remove the head).

If it does stumble or die, you have a control or feedback problem. Your EGR may be working fine, and just isn't registering properly. Ford uses a DPFE sensor that reads the exhaust pressure drop across a fixed orifice during EGR function. Most often, an EGR code on a Ford is a bad sensor, not the EGR. GM monitors EGR flow by reading the MAP sensor. EGR function has a direct effect on engine vacuum.

Any way about it, in the 18 years I've been fixing cars, I've seen a lot of disconnected EGR's. This is most often done by people who don't know any better, and think such things decrease performance. The fact is, there are no negative effects of an EGR, and plenty of advantages. I've changed many head gaskets that were burned hole-to-hole. Just finished one two days ago on an Isuzu. Any coincidence that the burn was between two exhaust valves? Not really. The valves were not burned, and the valve adjustments were correct. The EGR hose was disconnected, capped with a screw. Sadly enough, when connected, the system worked fine.