The new sensor from Firebird Cental worked as it should. If you test with a Mityvac you get between 5 and 10 inches of vacuum at the sensor before it vents into the air cleaner. The bad one vented at 1 inch and became a serious vacuum leak. The replacement operates the hot air flap correctly. They sent me a return label in the box so I could send the bad one back. An excellent company.