The first thing to check is the condition of the ignition components, particularly the plug wires. Check the EGR by lightly tapping on the valve while the engine is idling. If the idle problem clears, the valve is sticking. Considering the age and likely mileage, it is possible for the fuel pump and filter to require replacement, causing a lean condition. I have also seen filthy throttle bodies and dirty idle air valves improperly control idle speed as well. Food for thought...Ray