My engine is half the size of yours (3.2L) but I had a simular problem, lots of codes, the foul smelling smoke was fuel, she was running rich. Checked injecters, slide actuator, replaced wiring harness, air mass sensor, & O2 sensor. Turned out to be the engine control module (ECM) This problem is becoming more popular as the ECMs are getting older. The ECM sends false codes and shuts down some cylinders. I hope this is not your problem.