Try connecting SIL wire to pin #2 instead of #7 on the OBD to see if that changes anything
I will try that.
One other thing I was thinking of trying (after researching all afternoon) but ran out of time (I'm at work now) was switching the SIL wire to #15. From what I found the 98 uses ISO9141-2 protocol for data communication. According to the info I've found, the OBD port has two ports that were dedicated for that protocol. Pin #7 and pin #15. I'll try #2 and #15 tomorrow and see if either make any difference.