well I gave info in first post this one I tried to delete.96 disco 155000 miles just got the truck. Has fresh plugs and wires yes they are the oreillys brand. Got some sti wires coming. truck runs ok but up fires and backfires through mid rpm range. I have a snap on solus ultra with up to date software.and its troughing me for a loop. This is my first land rover but I am a well seasoned mechanic and the readings are insane. The vss reading 40,000, incoming air reading -40, both rear oxygen sensors read 5.0 volts. The speedometer is also correct when driving vehicle. No readings change when sensor is unplugged. O2 sensors are my next step after plug wires.