no way to get it to work right. most a/f gauges are narrow band. meaning that if the ratio isn't somewhere in that narrow band, it can't read it. but most of the time, your car is operating in closed loop, meaning the ecu is continually changing the a/f mixture, looking for the best ratio. that's why your gauge just puts on a light show and pegs at rich when in open loop. next time if you're gonna spend money on an a/f gauge, get a wideband.