[88pathoffroad]

I would replace the bad O2 sensors first and then see how it goes. Sorry to only offer an expensive solution, but TONS of problems resulting in driveability issues can be caused by bad O2 sensors. If the bad O2 sensors tell the ECU that it needs more fuel it will send more fuel, which makes it use too much and run poorly. The knock sensor will not cause bad mileage or loss of power.