EGR Issues
I have a 94 Honda Accord LX and i got a check engine cell idicating Bad EGR Lift Sensor.
Ive heard that an egr can severely affect performance, but its gotta be pretty screwed up to cause much of a problem. If your engine is running way better with it disconnected then chances are it is your EGR.
Were you getting a CEL with the Egr connected? If not then it may not be your EGR it could be a couple of other things. Have you ever cleared your ECU and driven the car so it could re-program itself? When you clear the computer the computer has to re-learn how to make itself run. If your computer isn't right your car will run wierd.
Let me know if you have any check engine light codes coming on with the EGR connected and that will give me a hint as to what your issue is. As far as i know a bad EGR shouldnt cause severe engine misfire. Could be something as simple as fowled plugs.
Well get back to me.