I have searched and read until my eyes are bleeding! Some people say it's normal to lose some boost after the delete, some say it's not and you need a tuner. Before the delete, I could regularly see around 28-29 psi on the factory gauge if I jumped on it. Now, I see about a max of 20-21. I have no leaks that I can find and the truck runs just as it did before. I still have my EGR plugged in laying on top of the engine and don't have a check engine light-yet. Is there a definitive answer as to how to fix this or is it really considered normal to lose that much boost after a delete? I don't really want a tuner because I'm not looking to add HP, but if that's what it takes, then I need to save up. I also read somewhere it can depend on the strategy. Thanks for any help.

 

I only see 28psi when towing or under heavy load. Most of time I see 24-25psi. Tuned with EGR still in hole and plugged in but shut off with tune.

 

Do a turbo re learn, bet you had the batteries disco'd working on the truck?

 

Yes I did. Is that the VGT relearn? I cleaned the MAP tube and port tonight and was planning on cleaning the EBP tomorrow.

 

The EGR delete wont turn on the CEL, it will set a soft code, but it wont turn the light on. I never heard of loosing boost before and I have done 4 or 5 EGR delete's, I usually leave the EGR on the engine plugged in, so at quick look everything looks right, most cheap OBD tuners will turn off the EGR. having the overboost and then not enough boost is strange, dig you delete the CAT too? Yea clean the EBP tube and the map line, see what happens.

 

I spoke too soon. I got a CEL last night driving home. Need to get it read today. And yes, the cat fell off about 10k miles ago.

 

Before my delete I saw 26 to 28 and rarely 30 psi. After the delete, I was seeing up to about 24 at WOT for a split second then back down to 19 to 21, BUT the truck ran and pulled just as hard as before. I have a SCT and used Matt's tunes to keep from having the CEL.


I just made a 6 hour trip this weekend to pick up my fifth wheel. Pulled it back home and saw up to 26 psi on big hills. I never did go WOT though. The truck runs great but several people told me it was the nature of the beast that the boost seems to go down after the delete. Idk?

 

Ok, so I pulled and cleaned the EBP this afternoon and it was dirty. No blockage, but definitely gummed up. While doing this, I noticed I have a hole in the cool side intercooler pipe. Could this be the possible cause of the lower boost pressure? Rechecking for leaks elsewhere right now. I also had the code pulled and it was for insufficient EGR flow.

 

+ exhaust flow = -map. Basicly an incress in flow will reduce pressure.
Map -baro=boost
Seems to be an expected out come.
Fix the boost leak because you need to but dont expect a big gain.

 

Cheezit, thank you for the info. So from what I understand, I'll still be chasing my tail regarding the lower boost?

 

That has been my experience.

 

Thank you. I haven't checked it yet since I cleaned everything, so hopefully all the factors working together will make a difference.

 

After cleaning you really should try the relearn. This will relearn both VGT and EGR function. I am thinking this important even if it is chasing your tail, because now you have cleaned all sensors, things will be working best possible. Also important to check that MAP tune be and EBP tube. It's easy to do and will help you get the most out of the truck. Also, I find getting over about 20 psi boost takes a bit of a clear run and highway speeds and a hill. Otherwise only 20 psi even wide open, it's not until higher gears that it starts letting you build more boost and you run out of road quick in fptraffic or congested roads.

 

That's my opinion. For a test run with spirited driving should see about 19-21 psi. With good open run unloaded, or a loaded trailer, or a nice steep grade etc and 5th, 6th gear and TC lock-up... 25+ psi.



Josh

 

I'm planning on doing the relearn just as soon as I get the intercooler pipe fixed. I should have that done by tomorrow-fingers crossed. Thanks for all the help and suggestions. I guess if nothing else works, I'll just keep driving it. I will say that I seem to be getting better mileage in town now than I did before, but that may be due to the warmer weather.