I have a weird lean condition when I let off the throttle in my truck and start to decelerate. I'm running speed density in open loop and dfco is turned off for tuning purposes. The only way I can keep it from surging with the throttle closed is to jack up the ve numbers in the low map area below 25kpa to add a bunch of fuel to get it back to 14.7afr. Everything else with my tune has worked fine for two years now but I know that something isn't right with low map area being set to 120% ve when 30kpa and up is normal. Anybody got any ideas? Could be in the tune or mechanical? I have went over everything in the tune a hundred times and can't find anything unusual.