I have an 04 F150 FX4 with 55k. I have just noticed that anywhere from 20 mph - 45 mph, when i try to hold the accelerator at a certain speed, it feels and sounds like its not getting enough power to maintain, it lunges. Even if I put the cruise control on, you can still feel and hear the lunging sound. I am going to replace the fuel filter this afternoon. I am wondering if this could be the cause of bad O2 sensors or bad spark plugs/wires? I am at a loss here. Does anyone have any suggestions? or has anyone experienced the same thing?

 

I would suspect the fuel filter as well I had that happen with my old 86' Bronco back in the day and as soon as I changed the fuel filter it was back to running like a dream. Let me know if that fixed it or not just for future fyi,
Thanks dude