This is probably something that has been discussed somewhere already, but just felt the need to post this in case it happens to anyone else who might be scratching their head. I know I was up until an hour ago.

Back in Aug I bought an el cheapo EGR valve. I've heard so many times you have to have one for proper cooling fan ops.......also have read just as many posts you don't need it for the early builds. I guess I knew better since it always kicked in when needed, but did so anyway.
It was an el cheapo Woo flung dung special off of Amazon, didn't think it would matter since it's just basically just flapping in the breeze due to the fact the kids truck is deleted.

Anyhoo.....about that same time give or take, boost numbers started to drop off. I didn't really notice right away since I don't drive it often, would also add the cycling became erratic. Truck comes pulling up driveway, literally every time he came home, sounding like a freight train in notch 8, low rumble. Then five seconds later the whistle....no rhyme or reason whatsoever. Had a hard time making 22 unloaded, maybe a pound or two more towing.

Around this time also stared to see P006B and P132B(only did this twice) popping up on occasion. I was convinced at least P006B had something do with that darn AFE air filter intake and oil messing with the MAF sensor, that said it never did it before.

Fast forward to two weeks ago. Finally had some spare time after field work, high school football, etc. was done, time to pull the turbo for a cleaning and rebuild.
Turbo was not that bad, and it had the updated thrust bearing. Rebuilt and cleaned anyway for good measure and the experience of a first time rebuild.
Stuck turbo back on, no change.......none.
Did a re learn, no diff.
Checked the VGT solenoid, tested within specs for resistance.
New hot side CAC boots......nada. They were originals from what I could tell, so that was more of a PM item but I was still hoping they would help as they are getting pretty cracked.
Cussed a little bit.

After someone mentioned checking for y pipe leaks, did that as well. Found I had a leaking drivers side bellows, and after getting it out the up pipe delete section had a leak as well.
Got the BD set up, installed, tested, boost was actually LOWER this time.
Not a happy camper.
Took the whole !@$# works loose as I was pretty sure I heard a leak, sure enough had bad soot build up about half way around the turbo connection. Started at the TOP side this time as you normally do, worked my way down as a few others have done..gained about two lbs, so felt better about that at least.
At this point I was about ready to just live with the lower numbers, after all it is running fine and not "low" on power. As some others with the BD y pipes have said, they saw slightly lower numbers.
That said, just not quite "happy" to settle for that.

This morning just for kicks I told the kid just unplug that EGR and see what happens since it seemed like this all started around the same time I installed it.
He called me back on the way to school pretty pleased.
24/25 lbs unloaded quite handily, and also said it responds a bit better low end with the BD pipes vs OEM and runs more like the scalded cat it used to.

Not sure what it will make for boost loaded, will find that out soon, but sure do feel better knowing that somehow that EGR valve was messing with something.

For those that know more about EGR valve and turbo boost I would appreciate any insight.
Are the two in fact related, and if so what is the correlation?

Did I just get a bad one since it was an el cheapo from China?

 

26/27 lbs now towing, back to normal once again.

Lesson learned if in fact the china made garbage EGR caused this.

 

Mike I would figure the EBP would have more to do with Boost than EGR. Going to follow this for my own curiosity.

 

This was the case initially yes, but the newer strategy that most of the early builds were updated with at some point took the EBP sensor out of the loop, it's an inferred value.

I really could not find much of anything anywhere, with someone having issues with low boost being tied to the EGR valve plugged in.

I know so little about how it(EGR valve) ties into VGT control, is the reason I posted my findings, and am still hoping one of the more "well versed" folks chime in on the programming side of things.

Maybe this case is unique, maybe not.
At any rate, it was driving me nuts.

 

Curious to know what happens if you plug the el cheapo valve back in. Does this bring the problem back?

 

Confirmed that the other day already, sure does.

I'm just wondering if it has something to do with the valve position sending a bad signal and what the PCM was telling the VGT solenoid?

 

This is interesting. I will watch it closer since I have the original valve.

 

There’s nothing more confirming then an A-B-A-B test.

 

Interesting. I might try unplugging mine. I’ve been wondering if I have a low boost situation at low rpm because my truck is a slug. It has poop, but no grunt, if that makes any sense. I hate working in that engine bay though so I tend to put off any testing.

 

Sounds like a good idea. It will certainly help other people visiting the forum.

 

What the hell?

My boost has been on the low side as well and I don't know the the full history of the truck. Now I'm going to unplug mine for ****s and giggles.

I'd heard the fan relationship and always thought that was strange, so half of me is surprised there's an interference with boost and half of me isn't.

 

What did everyone find out when they unplugged the egr,more boost,no fan,better mpg,all the above?

 

Didn't affect my fan.....period. Zilch, nada, nope. Still kicked in and out around 215* full on then backs off around 195 give or take.

For sure affected boost.........I actually posted this thread before I took the truck out to Togwotee and back with 9k lbs of snowmobiles and trailer, and in 4th gear with the TC locked in saw 29 lbs and even kissed 30 lbs just very quickly on one hill.
As far as MPG.........no idea yet.

 

I'm not sure anything changed at all on mine, I want to say I hit 25-26 max where I used to only see 23 but I'm not 100% sure. I'm going to have to do some back to back testing I think.

My fan has never come on so I won't be able to speak to that.

 

interesting... ive been wondering where my boost went. i may have to give it a try