I've just replaced my TPI intake and I thought that I put everything the way back as it was. I had a cardboard sheet with everything labeled. That being said, this plug snuck through and now I'm not sure where it goes. It's a two wire plug near the coil and connects to the wiring harness right behind the coil.

 

Egr solenoid, if not that mat extension plugs into it. Can’t tell your wire colors in the picture.