MustangForums.com - 4.0 V6 INTAKE EGR MOD - REMOVE RESTRICTION AND TURBULANCE

I found there is a slight restriction right at the neck of the intake plenum, behind the TB unit.

Behind the TB unit, is the EGR Valve bolted to the side of the intake plenum. The EGR valve
has a separate long curved metal tube that is directly in the intake air path. You can remove
the part, cut the curve out, and leave about 1/4" of the tube as a straight piece. Then you
reinstall the EGR valve and you should notice better response and a small HP gain.

This mod costs NOTHING, and takes about a half hour with basic tools. If you are an every little
bit of HP and throttle response counts kind'a guy, then this half hours worth of work won't hurt much.

Procedure:
Unhook the harness.
Unhook the two vacuum lines.
Remove EGR hard line, loosen the nut with a 1 1/16" inch wrench.
Remove the two 10mm bolts to pull the EGR valve off (save gasket).
Remove the two 5/16" bolts to remove the tube assembly from the plenum.

When you remove the EGR Valve, this is what is left in the intake plenum:
https://cimg5.ibsrv.net/gimg/mustang...65b52e780e.jpg
Make sure you do not loose or damage the EGR gasket. This would also be where you would place
an EGR blocking plate if so desired.

This is what you have when you pull that piece out. You have to pull it, and turn it towards the firewall
as you pull it out, carefully:
https://cimg8.ibsrv.net/gimg/mustang...91ceea14f6.jpg
You can see the curved tube, which is directly in the path of the intake air stream, which does
cause some turbulence, and restriction. It is said to be there for a more complete EGR flow.
The gases are pulled out by the intake air stream vacuum as it passes over the tube.

What you are going to do, is hacksaw that curved section of the tube off:
https://cimg2.ibsrv.net/gimg/mustang...f191edb586.jpg
Clean all the metal flings and burrs from the remaining tube.

Reinstall:
https://cimg4.ibsrv.net/gimg/mustang...591018b93c.jpg
Lightly lubricate the "O" ring before pushing that assembly back in.
Basically, you put the tube piece back in, then put the EGR valve back on it.

All done. There was no mention of any EGR codes afterwards. There should not be any, but if there
is a monitoring of EGR flow, not sure if the flow rate falls below tolerance to set the CEL. There was
no mention of that.

If anyone has done this, please let us know if you had any EGR codes.

Edit 11/13/18: After more research and finding other people on the net that have done this MOD,
there were no EGR codes reported by any of them, and they specifically said no codes where
thrown when asked.

Further more, blocking the EGR:
The EGR valve also helps your engine by richening up the air/fuel mixture but without
additional fuel. It does this by reducing the amount of oxygen in the cylinders and thus the
amount of fuel needed to keep a sane engine temperature while at cruising speeds. This
reduces the amount of fuel your engine needs to burn when power demands are low.

For a street car, there is no performance advantage to removing it and the only thing you'd
accomplish is wasting more fuel. Before you ask, when under heavy load, and WOT, the
EGR is closed. The EGR also remains open when coasting in gear to prevent "pumping
loss" when the throttle is closed. That's why you get manifold vacuum (and it can be quite
high, like 30psi or so). By providing the exhaust gasses to the engine when coasting, it's
almost like opening the throttle up a bit more but without producing more power or burning
more fuel. You're filling the cylinders with exhaust gases, so the motor is not struggling to
work against the vacuum being created by the pistons traveling up and down the bore.
The only real advantage to closing the EGR is a cleaner intake and motor.

This is different with Diesel motors, due to how diesel burns, the EGR robs your Diesel
motor of power and miles per gallon, you want more O2 to complete the burn on the
power stroke. Black smoke out the exhaust is unburned diesel fuel. Also, soot builds
up from EGR, it gunks up the MAP sensor, intake, and the EGR itself; thus hindering
readings that also effect performance. Plus, if you are tuned for rolling-coal at WOT, you
are also intruding that into your motor.

Removing or disabling the EGR is illegal, but in reality, it is not needed on a diesel motor.
It will increase NOx on both gas and diesel motors, but can hurt gas motor performance.
You do these MODs at your own risk.