Once you know the engine, you can either:
* Look it up online: Search "[Your Engine Size] Pontiac Grand Prix oil filter" on a site like AutoZone, Advance Auto Parts, or Amazon. These sites usually have filter cross-referencing tools that will show you compatible filters.
* Consult a parts store: Go to an auto parts store and give them your year, make, model, and engine size. They can quickly find the correct oil filter for your car.
Don't just rely on general advice. Using the wrong oil filter can damage your engine. Always confirm the correct filter based on your specific Grand Prix's engine.