Volvo S40 Stammering At Abrupt Acceleration

[piyush1]

i have a 2002 s40 and today i noticed while trying to pass someone on the interstate that when i abruptly accelerated, my car would shutter. if i gradually accelerated it was fine but if i really put my foot down on the gas my car would not quite vibrate as if the tires were out of alignment but it would stammer. I decided to test it a little so i quickly accelerated and kept my foot on the gas through the stumbling and saw my check engine light flash/blink at me. i let off the gas and the light went out. I was interstate driving for 140 miles and when i decelerated to turn off onto an exit, my car had some slight power loss. i wasn't able to accelerate for a second. when i had to stop at a light, my car stuttered again and my rpms would rise and fall, and it felt like it almost fell so low that my engine would have died. any suggestions what this might be caused by? I had someone pull the codes for me and the only code that showed was p0130 for o2 sensor which has been faulty for a while.