Do you have to remove the intake manifold on a Mazda 6 4 cylinder 2.3 L reach PCV valve?

No, you don't have to remove the intake manifold on a Mazda 6 4-cylinder 2.3L engine to reach the PCV valve. The PCV valve is located on the back of the engine, near the top. You can reach it by removing the engine cover and disconnecting the hose that connects it to the intake manifold.