Honda: 99 Civic LX check engine light on, leak down tester, honda dealership

Question
Hi there-
I have a 1999 Civic LX sedan (automatic) with 17,700 miles on it.  Yes, really!  The "check engine light" has come on and stayed on.  The engine is also idling slowly- about 1000 rpms and under.  The car seems too new to be having any problems and there is no previous service history aside from oil changes.  The car seems to be driving normally otherwise.  What could this be?  I'd appreciate any feedback or advice you have on this problem.  Thanks so much!

Answer
Engine Idle should be close to 850 RPM.  Check engine light and irregular idle lead me to a leak-down test.  It's similar to a compression check, except we measure the percentage of air that escapes each cylinder.  A compressor provides the air for the test.  You can buy a leak-down tester for about $60.00, and you'll need a seperate compressor.  My local Honda dealership had to borrow a tester from Honda North American headquarters.  All engines will leak some, newer cars (800 miles or less) will leak more.  You're looking for one cylinder with "abnormal" (high) leakage.  Find a trusted mechanic with a tester available to him and ask for this test.
Hope everything goes swimmingly,
Barrett.