Behind the right headlight .
Replace air pump
The starter for a 1999 Saturn is on top of the transmission under the air filter box. Remove the filter box for easy access.
All sensors, air pump, and EGR
under the air box
Air Conditioning Vacuum Pump.
To replace the secondary air injection pump on a 2001 Saturn, start by disconnecting the negative battery cable to ensure safety. Remove the air intake duct and any components obstructing access to the pump. Disconnect the electrical connector and vacuum lines from the pump, then unbolt it from its mounting bracket. Install the new pump by reversing these steps, ensuring all connections are secure before reconnecting the battery.
On the line right at the compressor.
To replace the air pump in a 2001 Saturn L200, first ensure the vehicle is turned off and disconnected from the battery. Remove any components obstructing access to the air pump, typically located near the engine. Disconnect the electrical connector and the hoses from the old pump, then remove the mounting bolts to take it out. Install the new air pump by reversing the process: secure it with bolts, reconnect the hoses and electrical connector, and reassemble any components that were removed.
The air pump or smog pump on a 99 GMC Jimmy is located right behind the bumper, below the radiator, and on the passenger side.
Right next to the windshield washer reservoir.
Posted a link under "Related Links" below
More than likely your heater core is plugged, and will need to be replaced