I have got a non turbo FC 88 model, i would like to know where is the location for diagnosis port? Any port inside the cabin? Also can i use that port to connect to a computer, so i can get all readings such as air temp, air/fuel, etc.

 

The only diagnostic port I know of on s4's is in the engine bay. All it does is tell if a few things are broken. If you want air temp and a/f ratios, you gotta install seperate gauges. I dont even know if the stock ecu monitors some of that stuff.