Hyundai Repair: Codes, air flow sensor, vacuum leaks

Question
Hi I had two codes come up on my 01 Sonata PO171 and PO720 can you help explain them
Thank-you

Answer
P0170 means that there's too large a difference between the amount of fuel the car needs to run efficiently and the amount of fuel the computer expects that it should need to provide.  This problem usually occurs because the amount of air entering the engine is not measured correctly.  Check for leaks in your air intake bellows and vacuum leaks (especially in the PCV hose).  If you don't have any unmeasured air entering the intake, you probably need a new air flow sensor.

P0720 indicates a problem with the output speed sensor on the transmission.  Almost every time I've seen this code, the problem has been the sensor itself.