P1131 2000 Ford F150 - what to do if code says there aren't enough o2 sensors?

Question

I have already put all new o2 sensors, a mas, and a fuel regulator. I did the vacume hose test and i didn't notice a leak. Before all this it just said bank one and two were to lean. Now after I've put all this stuff on its saying theres a lack of o2 sensors. Im at a lost

Answer 1

P1131 Lack of H02S switch sensor indicates lean

Exhaust leak prior to the H02S sensor can set this code,another circumstance  is when the H02S is not properly torque down .