So last night my check engine light came on. I went to AutoZone and they scanned it. Came back with a P0420 code, which says the Bank 1 catalyst system efficiency was below threshold for a predetermined period of time. They say I need to replace the catalytic converter(s). My question is, would it be better to replace the o2 sensors first and see what happens? There are no other codes so as far as the car is concerned the sensors are ok.
On a related note, about a month ago I had the piston rings replaced under the service bulletin for excessive oil consumption. The dealer did the test and determined it was using oil excessively. One of the possible issues with the converter (if it is indeed bad) is being fouled with oil from excessive oil consumption. Since the converter wouldn't have been fouled if the engine wasn't using excessive oil, would GM cover the converters and their replacement? As info this is a 2011 2wd 2.4L with about 109000 right now.
On a related note, about a month ago I had the piston rings replaced under the service bulletin for excessive oil consumption. The dealer did the test and determined it was using oil excessively. One of the possible issues with the converter (if it is indeed bad) is being fouled with oil from excessive oil consumption. Since the converter wouldn't have been fouled if the engine wasn't using excessive oil, would GM cover the converters and their replacement? As info this is a 2011 2wd 2.4L with about 109000 right now.