Manifold – Gm (25534416)

Manifold is an emissions or flow component in the exhaust system. Fitment is set by flange angle and sensor boss location as much as by pipe size.

Replace the Manifold when a code indicates the unit is below threshold, or when an impact or corrosion has breached it. Check the upstream sensor readings first, because a bad sensor imitates a failed unit.

Reference number for the Manifold: 25534416. It is filed under Throttle Bodies & Intake, and it is the number that has to match the part coming off the vehicle.

The stock here is genuine GM, and this Manifold keeps the original engineering number, which matters once a number has been superseded more than once.