Oldsmobile/Buick Repair: 1994 Olds, 88 LSS, OBD 1.5?, obd2 code reader, obd 11

Question
I have bee trying for some time to find out how to retrieve the codes from my car. I have read that it's not OBD1 nor OBD 11 but OBD 1.5. The connector appears to be OBD 11 but ohly has about 3-4 wires in the pins. Under the hood is a tag that reads OBD 11. Autozone code scanners fails to link to it. The car is stalling at various times. I soaked the EGR valve overnight in carb/choke cleaner and it seemed to help for a day or so. How can I get the error codes? Thanks.

Answer
that is the changeover year for gm. it should have an OBD2 DLC
and offer codes from both sorts. Autozone uses an OBD2 code reader. that is not compatible with your system. you need a real scan tool. I would ideally recomend a GM techI or TechII but any otc, snap-on, vetronix will do just fine.