The crankshaft position sensor (CKP sensor) on a 1991 Pontiac Grand Prix SE with the 3.1L V6 engine is located on the passenger side (right side) of the engine block, near the front of the engine, typically close to the oil filter. It's usually mounted on a bracket or directly to the engine block itself. You might need to remove some components (like the oil filter) to get a clear view.
Because its exact placement can vary slightly, a visual inspection using a repair manual specific to your 1991 Grand Prix 3.1L is highly recommended. A repair manual, either a physical copy or a digital version, will provide diagrams and precise location details to prevent damaging nearby parts.
