I just received my O2 sensor from Ramchargers, but I have a question about the part #. The part they sent me has the GM # 25162600 (AC# AFS-81). Is this the right part? The GNttype website lists the part # as 25162693 (AC# AFS-20). Right when I saw the sensor it looked funny to me. It has the purple wire, but the base is longer. Anyone know what the story with this is?