[yotermanic]

I'd look at the coil. Sounds like an ignition miss. Never hurts to re-inspect the plug and make sure there was no problem with the install/faulty part. Anything fuel-related before the injector should affect all cylinders, or random cylinders. The fact that it's only cylinder six says it's a problem with the cylinder or the ignition to to the cylinder. The fact that it's not a constant miss accompanied with noise would point towards ignition over a base engine problem.