1995 Toyota Camry EGR Gas temperature sensor

I have a 95 toyota camry that runs fine from a cold start, drive it for like half or so it begins to sputter like it isnt getting any gas and then it wont go over 30 to 40 miles an hour and u have to really baby the throttle to even get it to move so it wont die. It comes up with two codes one is o2 sensor and P0401 which is egr air flow insuffficient. We have check egr valve, modulator, VSV, hose vacuum lines everything and it all is fine and works, the only thing is we cant test the EGR Gas Temperature sensor could it be that? Everything was taken apart and cleaned so there is no carbon buildup.