I have tuned a few car's here lately that have had some really weird results with the custom OS's. Seems like the car's with boost and stock OS's run much better with less hickup's than the custom OS's have. Modifications to the VE table in some instances show's no change in physical fueling. Just wondering if anybody else has noticed the same thing with these E38/67's.
From now on I'm using all stock OS's for tuning until something is done with the custom OS's as far as stability.