I agree that it may have some influence on the mixing of EGR gasses. That is why I restricted them to the bare minimum. I disagree that it is there to compensate and direct the flow to the cylinders, compensating for a throttle body located forward. That just doesn't work for me after checking out the CPI V-8 diffuser.
It's purpose to smooth the throttle response is more plausible, IMO.
There have been many different opinions on this one. I respect Mr.Copelands opinion on this one, but disagree that it must be retained. The EGR system on the 2002-up engines is different and yet the diffuser remains?
CFM Tech throttle blade and Sonoma96's EGR limiterHenryJ wrote:A quick summary: The throttle blade diffuser is there to aid in mixing the egr gasses and equally distribute them to the cylinders.
Without it there is the risk of leaning the front cylinders, or so I was told.
With the diffuser removed, or by adding the CFM throttle blade. There is definitely a noticeable difference in throttle response. It is instant throttle. Almost too touchy when it is in low range IMO.
I added the EGR limiter to reduce the amount of EGR gasses being introduced. It was explained that the system was over engineered by 70%. It took quite a while but I finally found the line where I have reduced it and no longer get the SES light. I am using two separate limiters, one at the LH exhaust manifold and Sonoma96's at the intake manifold.
Now that I have said all of this ...the limiter only applies to the 2001 Crew Cab. The EGR system was redesigned for 2002-up, or so I have been told. As I understand it the valve is inside the intake manifold or in the head? Anyway it is not on the front of the engine like the '96-2001 s-series.
Here is the limiter thread:
EGR limiter
Steven is running the throttle blade too. check this thread from the old forum:
Throttle blade
I have been running one for four years now. I have gone back and prefer the mod to stock.
The lean condition for which there were warnings does not exist. I use the spark plug condition as indicators. They are even and clean.
I researched this prior to the modification. Answers are everywhere, but nothing concrete. I am reminded of the throttle spring hotrod. The story goes that two cars were offered for test drive. The question was asked which had better performance. The one with an extra throttle return spring was selected as having increased performance. The effort to press the pedal and the snappy return was interpreted as it having better performance.
Our trucks were marketed to the soccer grandmas, so a smooth throttle performance makes sense. In low range the throttle needs to be very smooth since the drivetrain reacts quickly.
Occam's razor states that the explanation of any phenomenon should make as few assumptions as possible, eliminating, or "shaving off", those that make no difference in the observable predictions of the explanatory hypothesis or theory. In short, when given two equally valid explanations for a phenomenon, one should embrace the less complicated formulation.
To smooth throttle response is pretty simple. Mixing of gasses works too.
I do not believe that exhaustive research goes into optimum engine design. Yes there is some, but more than often they take what they have and make it work. Crisis management. If there is a problem , fix it. Changes are more likely to be made it the name of safety, or emission standards than performance and design perfection. I am sure you can all recite several examples. I can think of several.
Thinking twice about any mod is good advice.
Do your own research and do not rely on only one opinion. Weigh the results and information to make your own conclusion.
I don't find it annoying in any way or in any situation. 
Yes, the CFM Tech blade is priced a little high, but it did fit nicely and I've had absolutely no problems with it in the past 65k + miles. 
That's just me though! 
Wow, I Bet That Doesn't Lead To A Happy Ending 
