Ford Taurus Owner's Manual page 61

Climate Controls
Note: A cabin air filter must be installed at all times to prevent foreign
objects from entering the system. Running the system without a filter in
place could result in degradation or damage to the system.
For replacement intervals, refer to the Scheduled Maintenance chapter.
For more information regarding your filter, see your authorized dealer.
61
2012 Taurus
Owners Guide, 2nd Printing
USA (fus)