Need to loop thru folder, save only the .xlsx files as .csv

Hello TDog and welcome to the forum,

Your code is close but it needs to remove the ".xlxs" file extesion from the name before saving it as a ".csv" file. I have modified your code to the following. I have tested it using Excel 2016 and works fine on my laptop. (changes are in bold)

Sub DirectoryFileLoop3()

    'Loop through files in a folder containing only .xlsx files and .csv files.
    'Leave the .csv files as is,  but save the .xlsx files as .csv files.

Dim fileDirectory As String
Dim fileCriteria As String
Dim fileName As String
'Dim fileToSave As String   ' not required
Dim fileToOpen As Workbook

Application.ScreenUpdating = False

    fileDirectory = "C:\Test\Directory\"
    fileCriteria = "*.xlsx"

    fileName = Dir(fileDirectory & fileCriteria)
    'fileToSave = Dir(fileDirectory)   ' not required

Do While Len(fileName) > 0

    Set fileToOpen = Workbooks.Open(fileDirectory & fileName)

        ' get file name without extension
        fileName = Left(ActiveWorkbook.Name, InStrRev(ActiveWorkbook.Name, ".") - 1)
        'MsgBox fileName

        fileToOpen.SaveAs fileName:=fileDirectory & fileName, FileFormat:=xlCSV
        fileToOpen.Close True
        'Debug.Print fileName & ".csv"

        fileName = Dir

    Loop

    Application.ScreenUpdating = True

End Sub
'

If this solves things for you please mark my answer as Selected

Cheers   :-)