P0420 and P0355 code given. Truck runs fine

I’ve been getting a check engine light on and off every couple thousand miles on my 2018 SR DCSB 2.7 2x4. The codes were p0420: catalyst system bank 1 and code p0335: crankshaft position sensor A. I know the 0420 code can be thrown occasionally from an o2 sensor or small exhaust leaks and there isn’t much to worry about unless it’s actually a bad cat. Which there is no evidence pointing to that. The crankshaft sensor code is what has me a little concerned. Everything seems to be running great on the taco. No rough starts, stalls, tach works fine. I should also mention that I left the oil cap off last week for about 50 miles and oil splashed on my timing belt and squeezed for a day but went away. Has anyone had a similar experience or have any tips on how to diagnose? Thanks

-B