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Smog pump bypass?

Let me respond this way. I have not done the kinds of dynamic testing from which you are looking to see data. Ford did that when they designed the systems. The purpose of the systems is to make the Federally mandated (and that would be the demands of "we the people" if you stop and think about it) emissions regulations for the model year of the vehicle in question. So, whether you agree with your fellow citizens that clean air is a good idea or not, that is the line by which Ford (and every other auto maker) has to abide. (If you happen to be in the minority on this political issue I would suggest you get to the polls more often and not tirade about it here).

So, with that said, I can tell you this. The systems have gotten exponentially better and less restrictive over time. Considering that the Federal Standard (OBD-II) system is a direct derivative of Ford's EEC-IV system (because Ford pioneered the idea of integrating rather than slapping on extra contraptions to reduce pollutants) it is a good bet that the system works pretty well and does as little as possible to inhibit performance given the technology available at the time of the design. The EGR and Thermactor systems basically disengage when the demand for performance is "felt" by the computer. EGR and Thermactor emissions are dropped out in favor of fuel delivery and timing adjustment as much as feasible given the standards set down by the Fed. Trust me, when I tell you that no auto maker EVER sat there trying to figure out how to take performance away from their products. They throw gobs of money at making vehicles that appeal to as many people as possible. The need for improved emissions and reductions in greenhouse gasses has spurred the return to alternative fuel vehicles and electric vehicles (and no, none of the AFVs we have today are completely new ideas).

The onboard computer will basically ignore input from the EGR and Thermactor if the need for power is "felt" (typically in response to throttle position and manifold pressure changes). However, at cruising speeds and when the engine really isn't working that hard to maintain the vehicle's velocity, the Thermactor and EGR roll in and start scrubbing away at the extra crud that the engine is belching. The nay-sayers either don't believe (or don't want to believe) this but its true. Because if those systems were just "always active" why would you need all the damned sensors and control devices connected to a microprocessor to calculate, recalibrate, and regulate them all? Think long and hard about that.

If you want to know the single most likely culprit when it comes to power and performance-robbing emissions equipment, look to your old, (probably cracked internally) catalytic converter or any other faulty part of your exhaust system. Exhaust restrictions harm more engines and rob more performance than just about anything. Why? Well that's easy, how many sensors and control functions are there on the exhaust? One, maybe as many as three, and all in the form of a completely passive (at least mechanically) HEGO sensors. The best a HEGO sensor can do is tell the computer, "Hey, there's too much fuel in this here exhaust...burnin' my eyes... might wanna back off the liquid diet and just breathe the air for a bit!" To which the computer will respond however, no matter what the ratio of crud-to-air in the exhaust, there is absolutely NOTHING to "tell" the computer, "Hey, er, um, feelin' a lil' constipated here. Can we slow down on the eating?.... all this rich food could stop me up and cause some damage."

In the end, (pun intended) it makes no difference what is happening on the inbound side. If the engine cannot "exhale" as well or BETTER than it "inhales", you will lose fuel mileage, throttle response, and in really bad cases, burn valves and kill rings.

Yeah, it can be a PITA keeping Thermactor and EGR systems functioning properly and yes, when they don't, it will adversely affect performance. But if they are kept in good working order, they will scrub the crud your truck produces much better and all without noticeable detriment to fuel economy or performance.

This response is going to get arguments about computer chips and modifications etc. Listen, the question wasn't about what MODIFICATIONS would do for the performance, the question was, directed towards "Will removing something help?" And in truth, with a stock vehicle, keeping it and the onboard systems all functioning properly will offer the best overall performance. Start a new thread if you want to talk about how ADDING or REPLACING things that attempt to alter performance or functionality can change things.

I have no idea if this will help but it is the most appropriate response I can muster given that I have and always will support the idea that performance can (and frankly should) take a back seat to our children being able to live on a planet and work on their own cars in their own garages long after we are gone without special breathing apparatus. (That is my little tree-hugger speech).
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The Token Canadian
Staff member
You might want to start a thread on you question as this one is kinda old...and welcome to the site!
Goodmorning y'all
The smog is the biggest crap I've ever seen on an engine in 35 years!!
The smog blows fresh air in the system two positions; under 2000revs just after the cat and above 2000revs straight on the exhaustvalves IN THE OPPOSITE WAY OF THE GASSTREAM!! How stupid can that be!! Because that cold ray of air blows exxentric on the valves, they will deform..
The cold air lowers also the exhaust gastemperature and moist in the muffler will shorten life of it. My truck is just 7 years in Holland.. One can see that all the bolts and nuts are undamaged, exept those of the exhaustpipe/headers... they are worn; I had to machine new ones. It tells me that the exhaustpipes are replaced a lot.

I've blinded off the EGR as well and MPG is improved, smoother run, more power and my engine remains clean. when I bought her, a thick layer of tar was in the inletmanifolds and the valves were damaged by all the tart what was sticking on the valves.
Let it be clear; an EGR is a gov. thing , only for the environment.
without the EGR, the O2 shall always cooperate with the EEC to reach the stochiometric value of 1:14,7 gas/air.
The inert gasses from the EGR lowers your combustionspeed (actually your timing retards) lowers the combustiontemp (powerloss) and because there's a natural law that say's " to keep a body on a certain speed, a certain amount of energy is needed to maintain on that speed". In other words, when the EGR is on duty, one shall push the acceleratorpedal deeper to keep speed. when I blinded it off, the first thing what I spotted, was the the pedal stood higher at same speed.
Now, they say that the EGR takes care for a lower NOx, okay? but when it messes your combustion, more fuel goes thru the engine and a lot of unburned will leave the tailpipe.
One must not forget, that the carmanufacturers and the oilcompany sleeping in oneand the same bed!! If your car can cope the environmental demands, it's okay and if the fuelconsumption rises, it's super to them!! All Gore happy, oilbosses happy, and as an extra bonus for the aftermarket sales, more work to do for carmechanics and more parts to sell.
Cars, oil and environment is pure politic games and we, as ordinary people are the"milkcows"of the governments.

This summer I've installed a woodburner in the house and 20cubic yard of wood behind the house is waiting to get burned this winter.... Environment? To leave a tree rotting away for years seems to make more CO2 than a quick burn in a burner... the Nuon(dutch natural gas company) shall not become rich over my back. but that was offtopic!!

best regards Ton
What do you mean by blinded?

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