To find it, you'll need to:
1. Consult a repair manual: A Haynes or Chilton repair manual specific to a 2001 Chevy Impala Police Package will be your best resource. These manuals usually have diagrams showing the AC system and clearly indicate the recharge port's location.
2. Look closely at the AC lines: The low-pressure side (usually thinner line) is more common for recharge ports. Follow the AC lines from the compressor and condenser. The port will often have a cap or a fitting that looks different from the other connections. It may be near the firewall or under the hood near the front of the vehicle.
3. Search online forums: Try searching online forums like Impala forums or automotive repair forums. Someone may have posted photos or detailed descriptions of the location for a similar model. Be sure to specify "Police Package" in your search.
Caution: Working with car AC systems involves refrigerant that is under high pressure and can cause serious injury if not handled properly. If you're not comfortable with this type of repair, it is strongly recommended that you take your vehicle to a qualified AC technician. Improper handling of the refrigerant can also harm the environment.