Why won't My 1996 Ford Windstar won't pass emission?

Bless You for your quick response. Someone is coming to look at it this evening. If you could please tell me where that little roung circular screen goes. I believe the guy put it in wrong. It does not go in front of the Mass air flow. I distinctively remember it in the back of the smaller accordian housing of the throttle body (black cone shape housing) by him placing it in front of the black air flow sensor, and cleaning it with carburetor cleaner and not electrical cleaner, caused the black leaking substance in the housing as well as thew black smoke. Get back to me please, ASAP

carb cleaner may have destroyed the sensor and if its wrong the wires will be very taunt and should not be.the sensor is normall a little closer to the throttle than the long side. the screen part goes to the fresh air side and acks as a filter kinda