who owns/uses a LM_2?

They don't work with open exhaust. The sensor is reading open air during reversion thus giving it fits. I have a AEM and it does the same thing. My buddy's challenger has electric exhaust cut outs and with the exhaust closed the idle reads fine, but as soon as you open the cut outs the reading leans out and goes erratic. Full throttle will read fine though as the reversion goes away at high RPM. Just can't tune idle and part throttle will open headers.