Subaru Repair: Subaru Forester w/same hiccup, spark plug gaps, intake manifold gasket

Question
I'm sorry you have endured some uncalled for comments in the past, but I'm thankful to have read that last Baja problem because my 1998 Subaru Forester does the same thing.  It has a hiccup at idle and hesitation in take off; between 1800 and 2300 RPM usually.  I haven't checked the spark plug gaps yet nor the upstream oxygen sensor, but the most recent dealership diagnosis showed nothing wrong.  It has come home in the past with a diagnosis of a third cylinder misfire, previously, but without reason or explanation.  I'll check the gaps to start, but I'm a frugal teacher and like doing things myself first so the sensor may have to wait.  Any other advice?  I definitely appreciate you putting your time into this advice forum.  Thank you,

Adam

Answer
If you are getting a third cylinder misfire, I would check to see if you have a vacuum leak near that cylinder. A cracked vacuum hose or even an intake manifold gasket leak. When you check the spark plugs tell me what number 3 looks like compared to the others. Color and condition. Thanks.