Mine was doing this for months. It ended up being a couple injectors. Not saying the new FICM tuning wouldnt fix it. It just took that long before it finally got bad enough to pick up a bad injector on the computer. When hooked to the computer and drove when it ran rough #2 and 4 were a little off from the rest. Then #2 went out so replaced 2 and 4 and wolla problem fixed.