I forgot to mention that i paid 700 $ ( including labor ) ??? Whatdo u think?

I did a test drive today and i noticed that everything good( acceleration from a stop, 0 60 ).........but i m still facing the same problem: when i put it in m mode in 2 gear and go slowly to 2500 -3000 rpm and then smach the gaz pedal the acceleration is huge and the rpm climb quikly.( when the x is cold) but when it is warm the same acceleration isnt as fast as the first one ( like i lost some torque). Could it be bad ignition coil or fuel injector??

Good to hear your'e moving on ) very nice. Actually, depends on how cold truck is when you are accelerating. To tell you the truth, on cold engine, it pulls better. not too much difference, but some say so. It also wrecks the engine as the oil is still cold. Good thing, Check computer, if bad igno coil, usually a missfire occurs. Not sure on this one.

I spoke to my mechanic and he said it s a failing fuel pump. But i wont replace it until it fails and throw a code

Today i noticed that the problem exists only in m mode . In sport my x is a different beast.