Land Rover Repair: Oxygen Sensors, land rover discovery 2, land rover discovery

Question
I bought my Land Rover Discovery 2 used back in November of 2005, My service engine light was on I asked the dealer why was it on he told me he used some low octaine fuel that caused the light to come on and when the fuel runs out it should go off, it never did I took it back to him complaining' he use a code reader to turn it off. After 25-30 miles of driving it camed back on. So now I figured maybe he was not honest. So I continued to drive the truck which began to cause me really bad gas millage, it is now August of 2006. So I replaced all four Oxygen Sensors after I took my truck in four a diagnois test which read o2 sensors and gear ratio. My truck is still not driving responsive as it should be' what else should I do to get this truck back to normal or very close?

Answer
The gear ratio fault almost always signals a bad mass air senosr.  OUtside of that tip, I'd suggest you find a qualified Land Rover specialist to look at your truck.  Most general repair shops are not going to be familiar with the peculiarities of these vehicles.