96 land rover when engine cold runs great on highway, when hot bucks at 70mph. Checked codes and P0340 comes up. Have changed plugs and wires, 02 sensors, and vss sensor and camshaft sensor. Also new fuel filter. Any advice will help

 

P0340 is Camshaft position sensor..Since you've replaced it you might want to check all the connections between it and the computer.. Probably I'd start by pulling and cleaning the big connector at the computer... And clean up and seal the computer while I was in there...

John

 

Should be capable of running with cam shaft sensor unplugged, it will force computer to use a fall back value. If it still acts up, consider the crank position sensor (rear of engine) and pouring cold water on it. If that clears it up it could be that sensor instead. You mention camshaft sensor, sometimes these are confused (CPS vs CKP)