Procedure on these is a little different. You need to run the codes with the engine off, and then start the engine and run them with the engine running. It's likely you have KOER codes, and not necessarily KOEO or CM codes.
You do not use the OBD-2 port under the steering wheel. The connections are in the same spot as a 86-93 car. Behind the driver side strut tower and in front and down of the wiper motor.
That nice of a car, I would buy a star tester for it
I only paid 50 bucks for this one
You need to do the running test too KOER
It should have saved a code either way if nthe light came on
I take it, the light is now off?
If you wanted to get real serious
That 1994 Cobra will display pids too with a NGS and the right cards,
You can watch the O2 sensors switch with one of these