How do you put freon in a 1998 Buick Riviera?

To add Freon to a 1998 Buick Riviera, first ensure the engine is off and locate the low-pressure service port, typically found on the larger of the two AC lines. Remove the cap from the port and attach a refrigerant can with a gauge. Start the engine and turn on the AC to the maximum setting, then slowly release the refrigerant into the system while monitoring the pressure gauge to avoid overfilling. Always use the correct type of refrigerant as specified in your owner’s manual and consider consulting a professional if you're unsure.