Hey... I live in Fort Washington, MD...
You should let forum members know when you are in the area!!...
I would think that you should have made 300 miles on a tank of gas at least.
When is the last time that you performed a basic tuneup? This could be as simple as old plugs, old wires, old rotor, or cracked dizzy cap. Or your throttle body is simply dirty.. I would start with a basic tuneup w/filters & PVC.
Also, how many miles on your O2 sensor?? Maybe time for a new one?