Land Rover Repair: wont go over 50 miles

Question
my 04 range rover wont go over 50miles wondering  what could cause this. Any suggestions?

Answer
You say your Rover won't go over 50 miles an hour, and ask what could be wrong.
Here are a few ideas:
- The transmission may not be shifting and you're stuck in 1st or 2nd gear
- The transfer case may be stuck in low range, giving a top speed of 40-some mph
- The catalysts may be clogged so the engine has no power
- The engine could have some other problem

Your first step is to determine if the problem is in the engine, transmission, or transfer case.