AFR during cruising

[F150Farmer]

Is there any way to change the air fuel ratio while in closed loop on an ecoboost? I'm trying to squeeze a bit more mpg from my 2014 f150. Ive tried upping the cold table ect to the point where it should stay in open loop, but it still tries to stay in the 14.7 range (just looks like it swings up and down further). Thanks all

[Higgs Boson]

no there is no way to change the AFR in closed loop. the whole point of closed loop is to correct to stoich, which is lambda 1.0.

cold base table isn't how you put it in open loop, you do that with the O2 sensor settings.

[b4black]

If better fuel economy were that simple, I suspect the OEMs would all be running lean.

[F150Farmer]

They do in other countries. America has strict NOx standards. NOx cannot be removed with a 3 way catalyst in the presence of excess oxygen in the exhaust. So while running lean, NOx pollution is worse, but results in better fuel economy.
In the O2 sensor settings, would the best way be to raise the O2 sensor temp to something it will never reach? The other open loop would be power enrichment, but I definitely don't want to use those settings for a makeshift lean cruise.