Anybody run a diagnostic tool on their engine and know at what load it goes "closed loop." I have a friend developing a plug-in that will run between the ECU and the fuel injectors - apparently larger gains can be had if the factory ECU goes closed loop relatively early, or is completely closed loop. If you don't know what I'm talking about, don't ask, because I don't really know myself.

 

My understanding is that closed loop is when you have the cruise control set and then ECU is set to the most lean condition the engine can handle. Playing with this should show no gains at all. I would stay away with playing around with closed loop.
If you want more information, I would PM DaveO.

 

If you watch with a consult, or obd reader, it is only in closed loop when idling, and cruising. as soon as you step on the gas more than just a little - it goes open loop. There is also an rpm limit for closed loop, I am not sure what it is but probably around 3,500-4K. After that it goes to a fixed map.

What I want to find out is if the long term fuel trims learned in closed loop mode are applied in any way to the open loop map.