An injection molded screw retainer is employed on an air intake manifold system to retain screws which connect an active system body to a manifold lower assembly. The retainer is substantially "L-shaped" and includes a retaining portion and a substantially perpendicular attachment portion. The retaining portion includes a substantially hemispherical feature positioned substantially over the head of the screw. The oversized attachment portion is inserted within a pocket in the active system body. Ultrasonic energy applied by a sonic welding process slightly melts the outer surface of the attachment portion, creating a weld interference between the attachment portion and the pocket, securing the attachment portion within the pocket.
