my car is doing this. at full throttle around 4500rpms the car sounds like its missing and back fires and looses alot of power. it started doing this 2 days ago. im thinking maybe it was a bad tank of gas? what are symptoms of the knock sensor retarding the timing?

im going to change the plugs. the wires i got are bwd automotive 7mm wire, and i hadnt been having problems with them before.