uuchk: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/sbin/uuchk - from package: uucp

You may install the required package with command yum install {package}

Error in other languages:
uuchk: bevel nie gevind nie
uuchk: comandă negăsită
uuchk: comando não encontrado
uuchk: commande introuvable
uuchk: command not found
uuchk: käsku ei ole
uuchk: không tìm thấy lệnh
uuchk: komanda nerasta
uuchk: Kommando nicht gefunden.
uuchk: kommandot finns inte
uuchk: komut yok
uuchk: nie znaleziono polecenia
uuchk: níor aimsíodh an t-ordú
uuchk: no se encontró la orden
uuchk: no s'ha trobat l'ordre
uuchk: opdracht niet gevonden
uuchk: parancs nem található
uuchk: perintah tidak ditemukan
uuchk: príkaz nenájdený
uuchk: příkaz nenalezen
uuchk: команда не найдена
uuchk: командата не е открита
uuchk: 命令找不到
uuchk: コマンドが見つかりません