If you're not finding events for those codes, then they aren't being triggered to create an event. If you want or need to keep track of these logs, I'd suggest creating a custom table or module and log them there so you don't have to deal with the event log automatically cleaning them up. I'd also suggest when creating your custom table records, to turn off event logging so it's only writing the record to the custom table and not both the custom table and writing an event for creating the custom table record.
You can do so by using this code:
using (var ac = new CMSActionContext(){
LogEvents = false,
LogSynchronization = false,
LogIntegration = false,
LogWebFarmTasks = false
})
{
// code here to insert custom table record
}