My son has a 88 n/a with starting and idling issues. Is the codes connector somewhere else other than behind the drivers headlight on his car. We both have looked and I even showed him what it looked like from my 91 S5. That plug simply isn't there in that location. So where is it?!!

 

I don't think S4's had "code connectors"

 

It should be there. Right behind the lamp beside the battery. It is a six-pin green connector. In the same harness as the Leading Coil Pack and another green 2-pin connector. I just did a code check on my 88 SE last week. Used the two led method. Have you checked the TPS yet?