service engine light

Need to know how to run codes on '96 Riv. 115k. 3800 series. I have had the car for a year now and haven't needed service on it til now. had the fuel filter replaced, then my service engine light came on and is still on. Oxy sensor?

Also, ABS light is on, and trac. control light is on. those came on at other time periods, unrelated.

I need to learn to run codes, and where I can find a list of the codes.

Any help greatly appreciated.

You need an obd11 scanner, no other way, the abs will have to be scanned on a scanner with abs capabilities.