I have a 2003 Dodge Durango with 49,000 miles on it. Just recently the engine light has come on, and I noticed that it was running a little rough the past few weeks at start up and at idle. The other day my wife started it when I was by the tailpipe and I noticed black colored smoke followed by a very light purple colored smoke. The exhaust also smelled a lot different then what normal exhaust would smell, it had a strong burnt smell but not like oil burning. I've checked the oil levels repeatedly the last few days and there is no change in the level and the smoke has not happened again at start up. One of my neighbors said it may be the o2 sensors and that he took his out and cleaned them and reinstalled with no further problems. His truck is a Ram 1500 with the same engine as my Durango so maybe this is my problem? Any help would be appreciated, this is my truck for pulling my trailer for now so I can't afford to blow it up. I was also thinking of just taking it to the shop and having them put it on the diagnostic machine to see if there are any fault codes.