Help Codes 14 and 21 2009 ULY

[DocSlick]

I have a 2009 ULY that has current codes 14 and 21. 14 should be engine temp sensor and 21 exhaust open/closed. With my scanner connected, the ECM is seeing a good temp signal.
Any ideas where to go with code 14. I have no idea where to start with code 21. I did clean the grounds, made no difference. The engine runs good and the cooling fan works. Thanks in advance for any help or ideas.