Engine Type L4, Engine Size 1.9L/116, manual tran, no mods.
When running at highway speeds, while accelerating to increase speed, engine cuts back as if governed, sometimes to the point of stalling, and degrades to 40 MPH and unable to speed up unless throttle is lighty touched. Codes pulled, P1443, P0420 and P1131, lack of Heated O2 switch 1, Evac vacuum system purge or VMV fault, cat system below treshold bank 1.
Recently fuel filter and fuel pump was changed along with the removal of approx. 2.5 cups of sugar. most vacuum lines replaced, new plugs and wires, properly gapped. No abnormal noises from engine (ticking, clanking, etc...) installed locking gas cap, when opened indicates negative air pressure inside fuel tank (air suction). Clean oil, air filter, good battery and charging system. Cooling system cleaned and parts replaced.
What could be causing this lack of power, what should I do to diagnose, and repair this problem.