jr70895

08 Silverado 4.8 check engine light codes keep coming on, time for inspection sticker and light on. Had it checked and codes said both front oxygens sensors and P 0121 Throttle Position sensor.
Reset codes and drove 150 miles and light came back on. This time only one oxygen sensor code came on.

I am going to change all 3 and try to get inspection sticker. Is there anything else that I need to check? Obviously I have issues as both Oxygen Sensors were changed 4300 miles ago. Truck has 240K miles runs good but always having issues with check engine light noting oxygen sensors. Had all 4 changed 4 years ago and as noted front 2 just 4300 miles ago.

Thanks

jr70895

Took to shop and they changed both upstream oxygen sensors and complete throttle body assembly based on codes showing up. Drove 50 miles and light came back on. P1133 code
"ho2s (heated oxygen sensor) insufficient switching sensor 1"

Not sure what that means. Shop said probably need to take it to dealer....????

I'm fairly sure he used Auto Zone parts, is it possible that Oxygen Sensors from Auto Zone could be the issue? Perhaps the truck doesn't like Bosch oxy sensors.....grasping at straws at this point.
Called the dealer and 3 weeks before they can take look at it.
The truck is running good just trying to get the annual inspection sticker.