sensor/catalytic converter

i went to autozone and put my car on the machine and it said it was the camshaft position sensor. when i put it in the shop they put it on their machine they said 7 sensors was out of range. but they said their was no way 7 sensors can be out of range. they said it could be one sensor thats triggering the rest of the sensors. so i called the chevy shop and i told them what the other shop said and the symthons of what the car is doing which is when i give it gas when i am driving it accelorate slowly and it wont pick up speed no matter how much gas i give it. when i get up to 50 MPH i pick up speed properly when i give it gas and when im on the gas for a while my speed starts to decend, when i take my foot off the gas and give it gas it speeds back up. and he told me it sounds like the catalytic converter. i dont think thats what it is cause it has no signs of the catalytic converter failing. can anyone help me, what do yall think it can be?

This needs a proper diagnosis, your description is too vague, too many things can cause this. The cat can be tested with a back pressure gage in the o2 port. What would you think other than some of your symptoms are signs of a failing cat.

Check the senser pressure gas it come on the top of pc volve