69428SCJ

Not to mention all the black soot and particles that were constantly on the rear bumper.

hillwood24

Yeah for real. On that note, once I installed a K&N short ram intake, the soot almost disappeared completely. Leaning out the system really helped eliminate the carbon soot.

69428SCJ

Had a COBB SRI on ours but it still did it. It got a lot of highway miles put on it and I would really air it out the last 3 miles off the highway to my house. Amazing how much soot that little guy would blow out in second and third gear after 1K on the highway. It was a 2010 with stock programming. We had it for almost 2 years and 70K miles...never did come out with aftermarket tuning when we had it.

Jaws1

My truck has almost zero soot. So little that I can run a finger in the tailpipe and it will only be slightly dirty. Aug 3 build date with 11k km on the odo. My Audi is also DI and the pipes are black. If the sooty pipes are a function of DI how is it possible that my truck has virtually no soot? When it was newer the pipe was dirty, but it has leaned out.

BoostedFx

Mine is not black, its just got a slight soot on it. I also was and wax my truck once a month so guess it would be hard to tell. My Titan never had any soot on the tail pipe so I guess that is why it caught me off guard a bit. But it makes sense being that the Eco is a direct injection engine with turbos. So soot on the Ecois exhaust is a good thing, that means everything is working right.

Blaine157

I use only top tier regular fuel and occasional Lucas Fuel treatment

ThreeOhTwo

Ford gasoline engines have not had EGR in quite some time as it has not been needed. EGR was developed in the 1970s when the EPA mandated limits on both hydrocarbon (HC) and nitrogen oxide (NOx) emissions. Everything in those days was either carbed (99.9% of cars) or had mechanical fuel injection. Those systems lacked the ability to monitor hydrocarbon composition in the exhaust and lean out the mixture if it got too rich (too much hydrocarbons in the exhaust.) So, the manufacturers made the engines run lean at all times. This raised combustion temperatures which led to higher NOx emissions. The manufacturers then diverted some inert exhaust gases into the intake of the engine to cool the combustion temperatures with EGR. This let them run lean mixtures to meet HC targets as well as not exceeding NOx limits. They also had other systems to meet emissions, such as early catalytic converters that required secondary air injection ("smog pumps") to work properly, PCV, and crude evaporative emissions controls to limit escape of gasoline vapors. This led to some very complicated emissions setups in the later 1970s and 1980s engine bays.

Since then, Ford as well as other manufacturers have developed successive generations of feedback/closed-loop electronic engine controls. This led to better control of the fuel-air mixture and ignition timing, and has obviated the need for most of the previous emissions controls. I can't say about the 6.2 Boss that was used in the 2011 Harley-Davidson and the '11-14 Raptors, but none of the other 2011+ engines have EGR. All of them have the same type of emissions controls, valve gear, and ECU capabilities excepting the naturally aspirated units do not have a turbocharger.

Soot is a known by-product of DI gasoline engines due to less fuel-air mixing than with conventional carbureted and port injection engines, as there is less time and distance for the mixing to occur. Fuel type also makes a difference as gasoline burns with much more soot than alcohol. I get a little soot in the tailpipe of my 5.0 if I run fuel with 10% or less ethanol, but if I run E85, there is none. It's not due to detergent. E85 has little detergent as only the gasoline portion has any detergent added, so E85 has typically 15-30% of the detergent as regular unleaded.