Emission's Light?

#1

I have a 2005 Ford Taurus sedan - 6 cyl - 3.0 liter with around 55,000 miles. The emissions light came on and when my mechanic went to read the code, it kept coming back as “not communicating”. I trust this mechanic (have been using him for years) and he insisted that his code reader was hooked up properly. Any suggestions other than taking it to a dealer which I really don’t want to do ?? The car runs fine.