ive got a 2001 supercrew with the 4.6 and running true duals. The true duals is how i bought the truck, but anywho, i started noticing the passenger side tailpipe is much more sooty than the other side which there is absolutely no soot whatsoever. I was trying to read up on this people are sayin alot of different things but mostly an ailing upstream o2 sensor and worse case scenario bad cat on the passenger side. Anyone here dealt with such an issue? any help is appreciated.

 

Unless you have a check engine light or drivability concern, I wouldn't worry about it. May be a product of asymmetrical piping and I assume there's no no X-pipe present to balance the exhaust pulses from either side of the engine.