The air filter in a 2005 Pontiac Vibe is located in a plastic housing
under the hood, typically towards the
front of the engine, near the engine's air intake. You'll likely see a large rectangular or slightly trapezoidal black plastic box. It often has a clip or latch securing the top.
To be completely sure, consult your owner's manual. It will have a diagram showing the exact location. A quick online search for "2005 Pontiac Vibe air filter location" with images will also show you exactly where it's situated.
