I have tuned two 05 Silverados lately both with mild cams and etc. Both tunes went very well in open loop with my wideband and both trucks were idling with good stability. However, on both, when the truck goes into closed loop it thinks its lean and adds fuel until the idle becomes unstable. I tried to set the PE parameters so that it would stay in open loop at idle by setting PE throttle to zero below 1200 rpm and setting the PE EQ to 1.00 in the same range. I also set STFT open loop to disable. No matter what I do, it goes into closed loop at idle. Am I missing something simple. I ended up leaving the last truck in open loop all the time and I'm meeting with the first guy to do the same on his but I don't like it. I should be able to get these guys trucks to idle. They're just not that extreme.
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