Thanks everybody for the suggestions!
I have an original Ultimaker. There are belt tensioners on the x-axis but not the y-axis (can't get them installed).
I did the following (all at once without an attempt to be scientific):
Attempted to install belt tensioners
Checked that all the set screws tight.
Reset the E steps back to the default value
Reset my Cura configuration
Played with infill overlap and ended up at 16%
The end result is I have a much better result. I am going to try and print up a better belt tensioner now and see if that helps.
Again, thanks for all of the suggestions.