Yes if your o2 or oxygen sensor is bad and not sensing the oxygen properly and telling the computer wrong information then you can have a loss of engine power.
Your engine will also run rich and may produce black smoke out of the exhaust when the engine is running rich and not running properly.
You can unplug the oxygen sensor to see if the engine runs better without it and if the engine runs better without the oxygen sensor then the oxygen sensor is bad and should be replaced.
If you can reach the oxygen sensor you can remove it and replace it easily yourself for just your time and the cost of the oxygen sensor.
If you have a shop replace the oxygen sensor then it could cost $100.00 or more to replace it.
The oxygen sensor is an essential part of the engine to help it run properly and tell the engines computer how much fuel is needed at a certain time.
Other things that could cause loss of engine power are clogged catalytic converter, bad spark plugs, bad ignition coils, bad spark plug wires, low fuel pressure, clogged fuel filter, bad or clogged fuel injectors, clogged air filter etc.