300 codes? Holy cow! Ok, if he cleared that many codes, there'* nothing wrong with your ALDL connector. I don't know what 1667 is. Not in my listing, but it'* not your connector. I don't think there are even 300 OBD2 codes available.
My bet is this guy had his scantool up his ***. No way your PCM was throwing 300 codes unless it'* hosed, or the scantool was. Go get another scan, and in the meantime, someone can chime in on the 1667.
Put your year and model in your signature. It'll help alot!