P1133 GMC - what is causing this

Question

3 years in a row. a new sensor each time. no fix. a new catalytic converter each time fixes it for a year then it starts all over again.........

Answer 1

P1133  H02S insuffient switching time sensor 1

In order for a catalytic convertor to work , the 02 sensor needs to go from rich to lean ,in doing so the catalytic convertor is mainly a mechanical device do its job in reducing and oxidizing. To do it job the 02 sensor need to be in closed loop, that means your cooling system needs to be in working order.Your not loosing coolant such as an intake gasket leak going into the combustion chamber,Motor oil, your not burning oil, or loosing oil , burning oil and coolant contaminates the 02 sensor,