Running open loop

Is there a way to force a 95.5 2.7 into open loop?
I have been put into a situation that I have to commute for work in the coma and found that while I am having issues with the trouble shooting of a long term problem, it uses less fuel when in open loop but have no idea what put me in open loop but now it’s back to closed loop and only getting around 10mpg. When it was in open, it was getting closer to 14mpg; would normally get 18.’

 

@Speedytech7 might be able to help if willing

 

source:%20Tacoma%20World
https://share.google/tcVDVa6aYZEPzz553

 

Unplugging the upstream o2 sensor will force it into open loop

 

That makes sense. That seems to be area my issue is anyway with codes 135 and 141 which I already replaced both 02’s.
Just got to nurse this senile old bitty for another week till I get the tundra transmission rebuilt.