open loop. what for? should i?

loop, open, closed, milage, poor, leave, ideas, power, sooo, ignoring, sensors, engine, controlling, guys, taking, signals, l[ike, l[oops, tuned

hi guys.. i know open l[oops is when the ecu is controlling the engine ignoring all other sensors and doing what it was tuned to do. and closed loop is when its taking signals l[ike the o2 and tps and all that. is there anyway to leave it in open loop? poor gas milage? my car seems to have sooo much more power before it goes into closed loop. any ideas?