I also have P0014 and P0024 codes. In my case I think the reason is over due Oil change. The labor cost is too high for this job. The mechanics are not willing to check the old sensors but they are asking to bring new ones and just change them regardless of old ones are good to go or not.
So, I'm getting the courage to do it myself. I'm thinking to remove the sensors clean them and then put them back. If I'm lucky the code will go. If not then I have to get the new ones.
Right?