symptoms- oil smells like fuel exhuast is popping....
you have a bad injector, fpr, or a bad mass air meter. you not only are leaking fuel past the rings into the oil but some of the excess fuel is running into the exhuast and igniting...
if you can put it on a scanner and look at your maf values if they are in range its a fuel system problem. you can chaeck the reg with a pressure tester and you can check for open or shorted injectors with a multi-meter.
hope this helps