Where is the fuel pressure regulator located on a 2004 Pontiac Grand Prix 3.8 liter engine?

On a 2004 Pontiac Grand Prix with the 3.8L engine, the fuel pressure regulator is integrated into the fuel rail. It's not a separate component you'll find easily accessible as a stand-alone part. You'll need to locate the fuel rail (usually on top of the engine) to find it.