I've searched for a definite answer to this but haven't found one yet. On an '05 6.0 does the PCM have to get a reading from the EGR valve to properly control the VGT? Reason for the question: the PO of my truck had the EGR valve and cooler deleted. There is a block off plate in place of the EGR valve and the plug that would normally plug into the EGR is just laying there not plugged into anything. My VGT is not functioning properly. It always reads in the 40's up to 50 at most. It doesn't spool up on startup like a 6.0 is suppose to do and it maxes out at 19 psi at WOT. I've already checked all my numbers and all are good except EBP sensor is bad, I'm replacing that today and I cleaned the tube as well. It throws the two soft codes for the EGR, I'm assuming because the PCM isn't getting a reading from it. I've also already checked and cleaned all of my CAC tubes and boots, they are good. I've also inspected my up pipes and they are clean, no sign of leaks. If the EBP sensor doesn't fix my issues that is gonna lead me to believe that I'm gonna need a tuner to fool the pcm into thinking its gettin a reading from the EGR. I know the VGT vanes being stuck are a possibility but I'm leaning toward that not being my issue here.

 

Okay I just found a thread talking about how unplugging the EGR valve can definitely cause the VGT not to function properly so now I have a new question. Can I take my block off plate off and put an EGR valve in there and plug it up to see if that corrects the problem? I know where there is an '03 or '04 truck setting that I can borrow the EGR from.

 

The egrs only job is to control the formation of nox gas. It is only there for emmisons compliance. Before emmisions regulation egr didn't even exist. An engine can run without it.
The egr works by allowing a small amount of spent exhaust gas to dilute the air to fuel ratio and cool the combustion temps to a level where nox is no longer formed.

The egr only causes problems when it malfunctions, allowing to much oxygen depleted exhaust gas into the system at the wrong times. Normal operation it only opens at a time or duration defined by the pcm which is quickly and only a small amount. Under normal operation you can't even tell it is working.

The VGT and turbo operation is controled by the pcm which comparers a number of sensor values. EBP is one.
I think your problem is more related to that than a egr issue.

 

The EGR valve is gone, but the truck has not been tuned? That could cause you more problems with the cooling fan too. Even if the EBP sensor fixes your boost, you will want to tune the truck if you are going to not put an EGR valve in there. Even if it's just plugged in, and laying on top of the motor, not in the spot it's supposed to be in, the PCM will be able to get reading from it.

 

The 6L PCM (especially on 05+) DOES require seeing the EGR valve signal for the Radiator FAN to properly function.

You don't need to actually INSTALL the EGR Valve, just find a used one and connect the wires to it and cable tie the EGR out of the way to the wires don't get chaffed/burned.. You CAN leave the EGR block plate installed, just connect an EGR valve to the wiring harness and the PCM will be happy.

 

Just take the EGR valve and plug it in and leave it lay there. It will get a no flow/low flow indicator but the truck will know its at least in place.

My 04 EGR is deleted and they threw the EGR valve away. No issues with the VGT because of it... however I am now having VGT issues because I think it's sticking... probably your issue as well. I've been driving the truck since last June when I bought it, issue just now surfacing... so I don't think the issue is ERG related.

Have read that the EGR effects the fan more so by being gone.

 

A missing EGR valve would effect the idle vane sweep operation of the VGT. It wouldn't effect normal driving operation of the vanes.

Josh

 

It's fixed! Put the new EBP sensor in and found an old EGR valve to plug in. Just let the EGR lay in the valley plugged in. Started it up and bam!! Turbo works like it should!! Thanks guys for all the help!

 

You know, to make it look better, you can put the egr valve in the hole it belongs and toss the delete cover.

 

I know, that's what I plan on doing. I just laid it in there to see if it worked.

 

I can't tell you how many times I've seen guys make that permanent.

 

I couldn't live with that. Its driving me crazy just knowing its setting that way out in the driveway! Lol

 

Tell you what, why don't you unplug the EGR valve again and see what the turbo boost does. A lot of people have said that they get low boost (max around 20 psi) with the egr valve unplugged and no tune to make it be ignored. Be nice to have an A-B comparison.

 

x2

 

I will do that today. What should max boost be on a stock truck. I saw 24 yesterday but I haven't had a chance to really get on it and see what it will max out at.