Thanks for the reply. How annoying then! After a few searches I guessed it was something to do with the ECU going out of Sync, but couldn't find anyone with issues after removing the ECU's. Right, I'll try and find the threads regarding diagnostics tools :o Thanks again

First of all, hello to all :) Right, I recently purchased 1998 Range Rover 2.5DSE for towing. I planned to chip the ECU, and was asked by a tuner to check the software number on the chip itself... So, I removed the ECU, and checked, re-installed the ECU about 30 mins later, and the engine...