Code 33 Oxy Sensor, but why?....

[Lopin18]

I know about the code 33, Check the oxy sensor according to the FSM (test with tester and ge blablabla amp volts whatever) and change it if its bad

But question, recently i had to change my CAS, so my ignition was moved from place, and i put it back in time randomly, trying to get it straight,

could it be that the Oxy Sensor is failing because of my timming? or maybe because my exhaust is full of holes (getting oxygen from outside??? XD)

ill test it according to FSM and change it but i would like first to test out if its happening because of X reason Help! Thank You!