Automatic Shifting Problem
 

Got a 2000 Civic with an automatic. Seems to shift fine through all the gears. But once you get out on the freeway and cruising the car doesn't seem to go into overdrive. What's wierd, sometimes it will go into overdrive (can see about a 400rpm drop on the tach). Since I drive about 40 miles on the freeway to work you can see where this becomes annoying not to mention expensive with the lose of mileage per gallon. The car only has 84k miles on it, everything seems and looks right. I'm at a loss as to what or where to check out. Any ideas? Thanks in advance!

Start with the basics and check your trans fluid level and make sure it isn't low and that the fluid is burnt, look at it and smell it and see if it smells burnt.