I don't think the straight pipe added any smoke, no smoke before (have no tune to ramp up fuel yet) and no smoke after the delete so that's good.I like the sound of that!
Did you notice any performance gain? I’ve read that there is no gain.
Does this cause any exhaust smoke?
I like the idea of more turbo diesel sound but personally don’t want any smoke.
Honestly I feel a small amount of power but I'm sure it's very small. I partly did the mod to prepare for a Stage 1 or 2 tune.
Edit: I recommend running it out to at least under the bumper... so not to trap the noise or exhaust under the car.