one flash on the ecu is oxygen sensor, surge in idle is the idle air control valve. thats on the right side of intake mani if looking down from the front of engine. could be a vacuum hose also. the idle control valve has a few small hoses coming out of it and has a cylinder looking shape. It sits right next to the intake mani, or the throttle body. I've heard of cleaning it with brake cleaner inside and out, but i never tried it.