2002 Liberty, 155,000 miles.

Have been getting the MIL coming on periodically for a P0302, Cylinder #2 misfire code. Replaced spark plugs which did not fix problem. Brought to dealer and they could see the code stored but could not determine the cause. Since car had been running fine, they suggested and perfomed a combustion chamber cleaning, which did not fix the problem. Also, said they have seen some Liberty's with valves sticking which could cause the problem. I found a TSB related to this but it is for 2005-2006 models. Most recently, the MIL came on flashing and the engine was definitely running rough (missing). Drove a short distance, turned car off and restarted, and the engine ran fine (missing was gone). MIL back to a steady light. Checked code, same P0302 code stored. Tried swapping the #1 and #2 coils but problem stayed with #2 cylinder. Light seems to come on once every 3 - 4 weeks.

Anyone else have a similiar problem?

You ruled out the coil and the plug. Because it's always the same cylinder that rules out anything like an 02 sensor, crank position sensor, etc.

It's a long shot, but you might want to swap the injector out of #2 with another cylinder. If it's not the injector it's probably something mechanically wrong with that cylinder. And since it comes and goes a sticking valve might be the problem.