My 1st land rover n I cant keep the engine running

[Melissa Thrasher]

I just bought my first land rover 2008 LR2
But I cant keep it running it turns on n within 3 seconds dies.
It struggling to stay in an idle so I ran the code readier and .3 came up

P0018
P0069
P0018
So far I have done an complete tune up n then bought the MAF sensor replaced it but still not staying on ... Help me please

 

[BoyMomx2]

Did you ever figure out what was wrong?