I have a 2003 disovery and the engine service keeps coming on ( around 8 or 10 times) on 2 occasions they changed 2 oxygen sensors about 2 months apart the other times they reset it and it seems ok only for a little while. The next time the service engine light on came flashing and I had it towed to a land rover dealer thinking they would be better at finding the problem they then changed another sensor .A few days later it came on flashing again so I towed back to the dealer they then decided it was not driven on enough and keep it a few days and then they said there was nothing wrong with it and to drive it more on the highway. Ok a few days later I am on the highyway going 70 for about 40 miles and what happens the service engine light is on again. PLease help me. I really cannot not go to landrover every week!!!!!!!!!!!!!HELP

 

When the light comes on again, go to a local parts store and have them read the codes for free.
Get the 4 digit fault code numbers and get back to us with them.
How many miles on your truck has it been tuned including wires?