Welcome to just answer.com. I'm here to help you and your 100% satisfaction is my goal. There are number of things that can cause this problem possibly a clogged catalytic converter or even a lack of fuel pressure from a faulty fuel pump, tell me what your fuel pressure reading is when you try to accelerate and also tell me what your intake manifold vacuum reading is using a Manual vacuum gauge. Let me know what you find and we will do some further testing if necessary I'll be with you as long as it takes to solve your problem so please reply back to me right here. Thank you very much.

It's not likely that it's a faulty sensor but it could be. If you remove the oxygen sensors from the exhaust system see if you have better power with the sensors removed this would indicate a clogged catalytic converter

Well it's easier to remove the sensors for testing purposes it will take much longer to remove the catalytic converter And you'll need to have a good catalytic converter on this or otherwise The check engine light will be on and you will not pass any emissions inspections

If the converter is broken internally then Replace the catalytic converter