Land Rover Repair: p0172 p0175, canister purge valve, range rover sport

Question
ive benen having the codes p0172 and p0175 on my 8000 km range rover sport 2012 for the 4th time, theyre failing to fix the problem, my exhaust tips are black from the black smoke that comes out of them, they checked my air filters and mass airflow sensors, they changed the canister purge valve, they updated the engine ECU software, they reprogrammed the engine computer, they performed a PCM module adaptation clear and again my check engine light is on again, my car has spent time at the dealership morr than with me, what do you think is going on. is this a defect ?

Answer
Exhaust tips are normally black on the inside on these trucks.   As for a defect . . . I suggest you call Land Rover customer service at the phone number listed in your owner's book and express your concerns to them,  They can work with your dealer to get the problem resolved so you are happy.

Sometimes problems like this need factory support to solve; sometimes the dealers have not got adequate training or experience  . . . if they can't help you should turn to the manufacturer.