1986 S10 02 sensor code with new sensor... What could the problem be?

What is your question?

I have made sure that there are absolutely no vacuum leaks. I have replaced the 02 sensor. I have given the truck a complete tune up. new plugs, wires, distributor cap and rotor. New fuel injector. New throttle position sensor. New fuel filter and air filter. I am wondering if my ecm might be bad or if there is a bad connection at the ecm.