2000 Cadillac Catera Owner's Manual - Page 256

NOTICE: Don't add too much oil. If your engine has so much oil that the oil level gets above the upper mark that shows the proper operating range, your engine could be damaged. The oil fill cap is located behind the engine oil dipstick and next to the engine block on the driver's side of the engine. Turn the yellow cap counterclockwise to remove it. When to Add Engine Oil If the oil is at or below the MIN mark, then you'll need to add at least one quart of oil. But you must use the right kind. This part explains what kind of oil to use. For crankcase capacity, see "Capacities and Specifications" in the Index. Be sure to fill it enough to put the level somewhere in the proper operating range. Push the dipstick all the way back in when you're through. 6-12