Shovel - Add Exhaust

[Eldora]

Please help me add exhaust to this shovel script.
Engine: Avesta 0.4

local MUD_HOLE        =    482
local duration = 1 * 60000 -- 3 minutes

function doTransformSandHole(parameters)
local thing = getTileItemById(parameters.pos, MUD_HOLE)
local newItem = doTransformItem(thing.uid, parameters.oldType)
end

function onUse(cid, item, frompos, item2, topos)
if item2.itemid == 28 then
  return 0
end
if item2.itemid == 468 then
  doTransformItem(item2.uid,469)
  doDecayItem(item2.uid)
elseif item2.itemid == 481 then
  doTransformItem(item2.uid,482)
  doDecayItem(item2.uid)
elseif (item2.itemid == 231 and item2.actionid == 4000) then
  doSendMagicEffect(topos,2)
  local randd = math.random(1,5)
  if randd < 2 then
  doTransformItem(item2.uid, 482)
  addEvent(doTransformSandHole, duration, {oldType = item2.itemid, pos = topos})
  doDecayItem(item2.uid)
  doSendMagicEffect(topos,2)
   end
elseif item2.itemid == 483 then
  doTransformItem(item2.uid,484)
  doDecayItem(item2.uid)
elseif item2.itemid == 231 then
  rand = math.random(1,35)
  if (rand == 20) then
      doPlayerAddItem(cid,2159,1)
  elseif (rand == 30) then
     doSummonCreature("Scarab", topos)
  else
   doSendMagicEffect(topos,2)
  end
else
  return 0
end
return 1
end