OBD II Problems
 

I have a 2001 mustang with the 3.8 L engine. My Check engine light was on so I plugged it into my tester, and it said the EGR was bad. I replaced it and the light went out. After driving it that way for 3000 miles I took it for PA state inspection. It came back saying that it was not ready to be tested yet. Any ideas why and how to make it ready?