Nissan Repair: 2000 Nissan Sentra, vehicle speed sensor, mass airflow sensor

Question
My 2000 Nissan Sentra has intermittently been idling higher than normal (between 3500-4000 RPM at 60 mph). In adddition it's been sluggish in it's overall acceleration. At times the overdrive light on the dash panel will flash. One garage told me I was imagining things, another diagnosed it as being stuck in "limp mode" and referred me to transmission shop where they replaced the Vehicle Speed Sensor. Had the car back less than 24 hours and the original problems still exist. I would certainly welcome any suggestions.

Answer
Dale,

The vehicle speed sensor was probably defective but that was not the root of your problem.  Most often on the Sentra it is the mass airflow sensor.  I would purchase a Haynes Manual and use it to show the test procedure before you plunk down money for a mass airflow sensor.  You will need a digital volt ohm meter.  Both the book and the meter are around $20 bucks each.  A good investment for the future.