GM Service Manual Online
For 1990-2009 cars only

The air intake system draws outside air through the remotely mounted air cleaner resonator. Once the air is filtered in the forward mounted air cleaner housing, the air passes through a duct past the intake air temperature (IAT) sensor through the mass air flow (MAF) sensor and throttle body into the intake manifold. The air is then directed into the intake manifold runners, through cylinder heads and into the cylinders.

If the MAF sensor is installed backwards, the system will go rich. An arrow cast into the plastic portion of the sensor indicates proper air flow direction. The arrow must point toward the engine.