idle/misfire/backfire problems

[aziankingz]

My ka24e misfires badly and the idle drops up and down, as well as backfires like crazy. I replaced the MAF, coolant temp sensors, distributor, coil, rotor/cap, fuel filter and spark plugs/wires and the problem still occurs. At random times the idle would dip to 500rpm when i press the gas. Anyone know what this could be? I also get really bad mpg - about 13mpg city and 20mpg mixed.. could replacing the o2 sensor fix the idle problem as well as the bad mpg problem? i also have an exhaust leak from my cat..would that cause a bog in the idle when i try to accelerate?

[reezn]

Did you ever get your idle problem fixed? I'm poking around right now for ideas.

[gtc_240sx]

open your valve cover and check if the chain tensioner is still there.... Driver's side