Sometimes when I have my foot off the gas, as in coasting or slowing down, and then I go to quickly accelerate the truck kind of stumbles a little. It is definitely not snappy when I try to accelerate from this. Is this a timing problem? I only have 20k on this truck so I am not sure why it would do this. I had the truck in for service to have the timing chain tensioner replaced at about 12k. Should I have an independent shop check my timing? Or is this something else?