Ford Repair: 1989 ford ranger 2.9 V6, vacuum pressure, battery cables

Question
I have just purchased a 1989 ford ranger 2.9 V6 4X4 standard. The problem I am having is that when I go past 2500 RPM the engine seems like it is out of gas and no power, idling ok. i changed the  plugs, wires, distributor, rotor button, and air filter, and it is still the same. Engine light comes on some times and then goes out. I had it scanned and it said O2 sensor miscommunication or something to that affect. I am replacing it tomorrow and also the fuel filter. what could e causing this?

Answer
when you replace o2 sensor be sure and check wires and make sure they are ok-always make sure battery cables are clean and tight-you could have an exhaust restriction also makes sure timing is correct and that is 10 degress btc with timing connector disconnected. if you have any doubts on backpressure from exhuast a local garage should be able to test it-if you have a vacuum/pressure guage you can tap into exhaust where 02 sensor mounts and rev engine to around 2000 rpm pressure should remain under 2lbs less is better. also do not rule out fuel presssure. good luck