Most of this is from Kodi Tips

OK first you need to edit some source code here, so if you don’t want to do that, look around for a new repo that has done it for you. I am placing what I have managed to pull off here mostly for my own info, and hopefully it helps someone else do the same or better.

Inside the source code of Exodus is a file referring to Trakt, and inside that file is the API keys for the original Exodus, you want to change these as decribe on the Kodi Tips page linked above. (copy below)

Exodus Trakt Not Working Fix

  1. Head over to Trakt.tv and login with your account.
  2. Click on Settings Your API Apps > + New Application. Enter in a name and skip the description.
  3. In Redirect URI, put: urn:ietf:wg:oauth:2.0:oob for device authentication.
  4. Skip Javascript origins, check the permissions /checkin and /scrobble boxes and click on SAVE App. 
  5. Write down your API Key and Secret key numbers and save them.
  6. On your Kodi box, navigate to the following file ~/.kodi/addons/plugin.video.exodus/resources/lib/modules (use ES File Explorer on Android or navigate on your computer via a network connection) and open up the trakt.py file in a text editor.
  7. Replace the following two lines: V2API_KEY = ‘Your New API Key Here’ and CLIENT_SECRET = ‘New Secret Key Here’ and save the file. Note that if Exodus updates and does not fix Trakt, you will have to edit this file again.
  8. Back in Exodus, go into the Trakt settings, click on your username, and follow the instructions on screen to re-authenticate Trakt again.

Now that being said, I noticed that this hack didn’t seem to last to long, so what I did was clone the Exodus source code, and just rename it. This way Trakt doesn’t know that you are using Exodus. If you want to get the latest updates for Exodus (like from some other repo that has an altered version of Exodus) you can add in your API keys and change the version number of your copy up one level, so that when the other repo updates you get there copy by default.