An electrical connector with a contact module includes an insulative body, a plurality of contacts retained to the body, and a grounding bar embedded within the body. The contacts include a plurality of differential pair contacts and a plurality of grounding contacts. The ground bar forms a plurality of spring tangs. The body forms a plurality of cavities and the corresponding spring tangs of the grounding bar extend into the corresponding cavities to contact the corresponding grounding contacts. Conductive adhesive is filled within each cavity and solidified to secure all the spring tang, the corresponding grounding contact and the body together. The electrical connector is formed by a pair of contact modules back to back secured to together by an insulative case either by assembling or via an over-molding process. The cavities and the corresponding conductive adhesive of each contact module is hidden from the exterior.