Thanks for your response. What's even more strange is that I decided to replace all the spark plugs, and it still kept sputtering.
Now here's the bizarre twist. I started having this problem when I joined Sam's Club and started using their gas. Then one day, I decided to use gas from QT because I was low on gas and was right next to a QT. Sure enough, the sputtering stopped. So now, I don't use Sam's Club gas and just use QT's.
Once in a while my car will sputter, but that's just after using fuel injection cleaner, but it'll go away soon afterwards.
