Land Rover Repair: Check enging light 2001 Disc, mass air flow sensor, mass air flow

Question
My check engine light came on and the PCM detected an incorrect gear ratio condition in the 4th gear (P0734. The truck runs fine.  This code is the only indication of a problem.  It also determined that the fuel system for bank 1 (P0171) and bank 2 (p00174)was too lean. They told me to replace the O2 sensors to correct these problems.  Is this what I need?  If not,  What is the problem and how can I fix it?

Answer
Don't buy o2 sensors just yet!

The three faults you describe point to a bad mass air flow sensor.  It's a $150 part on most models, easy to change.  Nothing to do with o2 saensors.

The codes do not signal a problem with the transmission, so do be worried about that.

You may want to read some of my magazine articles in the Rover News and elsewhere on problems like this, because I discuss testing in more depth.  Look on the Robison Service web site under service dept > land rover > advice > articles