This makes your Sandking blow black smoke out of the exhaust pipe.

Go to (your gta v installed location) Grand Theft Auto V\update\update.rpf\common\data\levels\gta5

then open the file labeled vehicles.meta

make a copy of that file and store it in a safe place.

then copy the lines from the smoke.txt file and replace the lines in your vehicle.meta file.

make sure you only replace those line and leave all the others untouched.

Hope you guys like this.