Motor was working great but now i have a whole bunch of problems...my car bogs btwn 300-700 rpm MOST of the time but not all. Sometimes when im driving, it feels like i just hit fuel cut, my car hesitates and when i step on the gas, i backfire like i have no spark...WHAT IS IT? It started at a race when i notice my rotor screw fell out and f*cked everyting up...i switched cap rotor, then coil and then the whole dizzy but it still has the same problem...before the race, i added a AIR/FUEL gauge...could i have a O2 problem????HELP PLZ

 

any codes?

sounds like you might be runnin rich. Check your plugs

 

plugs are good, brownish...but knock sensor started to pop up, no idea why...thats the only code......but now i notice when i disconnect my O2 sensor, the car doesnt hesitate any more but i still feel the lag and it still bogs...