Where is the low pressure port on 2003 Monte Carlo SS?

On a 2003 Monte Carlo SS, the low pressure port for the air conditioning system is typically located on the larger diameter line, which is the suction line coming from the evaporator. You can usually find it near the firewall on the passenger side of the engine bay. It will have a plastic cap that is often blue or black, indicating it is the low pressure service port. Always ensure the engine is off and the system is properly depressurized before attempting any service.