I have a 2017 Malibu Hybrid that brought up a P015B code. I had both O2 sensors replaced and 2 days later, same code popped back up. I took the car to the dealer and they diagnosed it and said I needed to replace both O2 sensors. I informed them I already had them replaced, and they said the shop probably didn't use OEM sensors, and they failed. So instead of paying $520 for the work they wanted to do, I ordered the Delco sensors from GM part supply and took the hour and replaced both. I ended up having to clear code myself, but after driving light came back on after about 90 miles. Clearing the code does same thing, it will pop back up after about the same time. I'm sort of stuck now, I don't believe (2) sets of O2 sensors were/are bad. Is it possible something else is causing this code?