B2200 CEL where is the diagnostic port??

Hi i have a CEL on my FI 1993 b2200 SE5.. i think its the o2 sensor but I just want to confirm.. can someone tell me where the diagnostic port is? and what the read outs for the CEL's are..

I know on my accord there is just a blue clip and you stick a paper clip in it to check and the engine light flashes.. is there something similar to this on mazdas?

if i'm not mistaken, the port is on the passanger side of the engine bay, where the wiring harness comes out of the fire wall....not sure what code it should read for the 02 sensor, my chiltons is @ the house otherwise i would hook you up with that info too...

I don't think there is a port My 93 CEL was hooked to the odometer, and you just switch the plugs under the dash.

There is a port of sorts.Green plug on the firewall,passenger side.But as posted above to turn CEL lite out,locare the CEL lite under the dash and move the plug from one side of the lite housing to the other.Lite should go out.I think the diag port only givesvery limited info and not sure if the o2 is part of that or not.BJ