Decided to use the DS4 and found a few bugs.

[Sparkz_360]

So i decided to give drifting a go with the controller, (loved it in GT6) i struggle with the wheel at the moment (i'm practicing don't worry ). Anyway i managed to maintain the slide the first time, tried a few more times to see if i was consistent (mission accomplished) but then, as it said "go" i pressed the R2 trigger fully only for the throttle bar to go up to 40%, could brake at 100% but 100% full throttle, it wasn't happening. I tried an arcade race to see if this still occurred, same result.

I then changed the button layout to X for drive and Square for brake (Classic GT Controls), could drive at full throttle, but no modulation whatsoever...

Well 50% in this case but you get the point. (R2 trigger pressed all the way)

Does this happen for anyone else???

 

[Guffaluff]

Have heard this before, but in all cases it turned out to be a fault with the controller. Sounds like it. Try mapping the throttle to the right stick and see what happens, or using another pad if you have one laying around.

 

[KingFrog]

Your triggers are faulty. The Dualshock 4 does not have pressure sensitive face buttons since IIRC only a dozen or so games used it last gen.