I have a 99 Range Rover 4.6hse. I have 2 codes showing. One is P0455- EVAP Emission Control system leak (Large) the other is P1562- Manf Cntrl Veh. Spd. Idle speed control auxiliary inputs. Any help would be great.

 

The gross leak could be any of the fuel lines leaking to rarely a really bad gas cap leak.
The 1562, haven't delt with that one for a long time.
How and where is your idle? You might consider cleaning you t/body and the idle control unit which may clear this up.