Community Forums

Waiter21 · 12-10-2018, 01:39 PM

Quote:

Question - is a functioning EGR tube imperative for the engine running smoothly, or is it strictly an emissions thing?

Yes , No, Maybe...

By reducing combustion temperatures, it reduces the creation of NOx emissions

I deleted mine mainly because there was no EGR port on the headers I installed. I installed a blank plate where the EGR valve was to block the intake. I then plumbed the vacuum lines to spoof the PCM into thinking the EGR system was alive and well..

Before making this decision I researched the EGR system extensively on the Ford Truck Enthusiast forums. (great source for V10 and 4R100 info)..

EGR can help improve gas mileage under low power conditions (low throttle settings) and reduce susceptibility to pinging because of the reduces combustion temperatures..

I note that my V10 rarely, if ever, operates under low throttle conditions.

In the reports I've looked at in the Truck forums, there were ZERO reports of degraded performance or gas mileage when users deleted the EGR. Typical reports were "I didn't notice any difference"..

Its important to note: If the PCM fails the EGR system, then its never activated and the CEL light will illuminate.. However, if the PCM thinks the EGR system is OK, it will signal to use it. It will also advance ignition timing when it thinks the EGR is open. This can cause a ping, maybe.

I'll be traveling next week so will be able to collect some data on this. Unfortunately, My data cannot conclude specifics to the EGR system because of the changes I made to the exhaust system (removed OEM exhaust and installed long headers)

Good read on EGR ::

https://en.wikipedia.org/wiki/Exhaust_gas_recirculation

..

spyderRV · 12-11-2018, 12:10 AM

"Its important to note: If the PCM fails the EGR system, then its never activated and the CEL light will illuminate.. However, if the PCM thinks the EGR system is OK, it will signal to use it. It will also advance ignition timing when it thinks the EGR is open. This can cause a ping, maybe."

Yes however, won't the knock sensor retard the timing. I get the dpfe fault code occasionally. Reset it and it's gone for weeks.

Waiter21 · 12-11-2018, 05:16 AM

Quote:

Yes however, won't the knock sensor retard the timing.

Yes, you'd think so, but I'm not sure what the strategy is: how much it retards or how long.

I'll be watching for this on our trip out west next week. I'm hoping I'll see a small increase in gas mileage, but I'll attribute this to the engine breathing better with the long headers vs the non-pi square exhaust manifolds. This improvement is significant under high power / high RPM conditions that my V10 operates in.

Last year I averaged 6.75 mpg over 7,000 miles. I'm expecting a mild improvement, maybe 6.85 or possibly even 7.0.

EGR SYSTEM - Mike - It really depends on how they perform your smog, and how much the inspector knows what to specifically look for. I suspect at minimum, they hook the computer to the ODBII port and verify all test are performed, passed, and no pending codes. i.e. don't show up at the inspection station 5 minutes after resetting any codes, because their computer will see that the test have not been performed.

If the system is intact with no visible damage (pipe broken off) and there are no codes set, then the EGR is doing its job.

NOTE - In the old days (1990's Calif) , they would hook up a hand held vacuum pump thing to open the EGR valve and then watch for a corresponding decrease in engine RPM to indicate the EGR valve actually opened. I don't think they do this today.

I recommend you get a ODBII scanner. This is one of the most useful tools I have. I have one of the inexpensive wifi ones I bought on Amazon.

https://www.amazon.com/BAFX-Products...M4G27JR5NYVVC0

I then bought the "Torque" app for my android smart phone to display everything I need to know, including transmission temperature.

This will tell you if all test have been performed, it will show any codes that are set, It can also show you mode 6 data and many, many special PIDs (i.e. Transmission temperature) that are reported. AND of course, it will allow you to reset codes and the CEL light.