I have checked the injectors, they were sent out, I have gone through everything, I have no idea, it doesn't even smell that bad when running and I don't have a cat. I have flushed the engine, it just gets black fast and I haven't been beating on it. I have done both compression and leak down tests, no issues there. In addition my fuel pressure gauge will stay at 42 psi for days and days after turning the car off, my buddies GN drops to zero pretty quick and he does not have this issue. My tune is not pig rich either, that's why I am scratching my beautiful but balding head.
The reason I was leaning towards cold oil, my Impala was not getting up to operating temp, the oil got dark very fast and did smell a bit. Upon changing the thermostat, (it gets to 195*), I'm due for an oil change but the oil has barely changed color and does not smell. I have just under 55,000 miles (90,000 km) on my car and it hasn't been beaten to death, I have owned it 8 years and knew the previous mature owner.