Low Boost Pressure After DP Install

[BHammzy]

Alright so I've seem to run into a little bit of an issue. I just recently installed a catless DP on to my car this past week. Before the DP install the car was pulling great, building boost just fine and everything. After installing, it seems that it's only able to boost about 5-7 PSI. I set the oil temp gauge to measure my over/under boost target and it seems to barely move anytime I get into boost. So I tried WOT and of course the engine malfunction light pops up with the 30FF code. I thought that my charge pipe may have been bad, so I replaced that this weekend to no avail. Next I had all of the vacuum lines checked to make sure those were fine and they seemed to be in good order. So now I'm curious as to what my next option would be. I've been reading around that the boost solenoid's may be a reason for the low boost pressure, which would be an easy fix, but I just don't want to go replacing unnecessary parts that I don't need to.

Other than the boost solenoids and wastegate actuators, would there be any other reasons for such a drastic loss in power? Would there be anything that I needed to do with the JB4 after the install of the DP?

Thanks a bunch!

[Goodmorning]

Im in exactly the same boat as you are juz yesterday after catless installed. So im dying to know as well what might caused it. Additionally on my end is that the SOUND of the downpipe is horrible!!! Totally different from footage i found on youtube(Same brand DP).

-havn't done the leak test just yet
-CP still look like in working order
-havn't thought of wastegate and solenoid before(should it be in my consideration?)

My mods are Cobb AP stage 2 sport, remus quad exhaust, and now raceland catless downpipe(if it helps at all)

Pls help the poor brothers out coz i cant stand driving around and sounds like a fart can any day longer

Thank you OP for making this thread and thank you in advanced for those who chime in as well.
Cheers!!!

[ShocknAwe]

You may have the o2 sensors reversed.

[Goodmorning]

ShocknWave on my case the installer told me before i mentioned about fitment that they knw raceland DP is a tight fit coz they did few of their customers cars b4, but i did ask him anyway abt o2 reverse and his answer is a big no

[hova00]

iam in the same boat after downpipe install. I had the car checked and the shop says no boost leaks but the 30ff code says otherwise

[rob24ert]

Curious to see what happens here. I just bought my DP but was waiting for warmer weather to put it in.

Are all the cars here N54? OP is N54, Goodmorning unsure, hova00 says M3?

[vtl]

Most likely you've put the vband clamps on the downpipes in such an orientation that it blocks the wastegate actuator. This prevents the actuator from closing, which in turn will mean the wastegate is still open and not produce much boost.

[Goodmorning]

Yup mine is N54 VTL.

I paid the professional shop to install the dp(2-3hrs), as for wastegate mistake how likely they can screwed this up by a professional esp when they said they've done several dp installed b4? Thanks

[BHammzy]

Mine is also an N54 engine. That vband clamp suggestion is one I'll definitely look in to. I was going to bring it in to a shop tomorrow to have i looked at so I'll mention that to them and we'll see what happens.

[mike@x-ph.com]

Couple things can go wrong with the DP install

You either have the sensors reversed (most common issue)
damaged O2 sensor during install
bad install, getting a leak
Bad downpipes

[heist_tub]

Vband clamps for sure. Mine did the same thing. Not allowing wastegate to work

[Goodmorning]

Juz went back to the installer to have 'em test drive the car and schedule me back next week to recheck on wastegate or whtever tht went wrong in the process. Im hoping its smth simple but who knws rifht? Will update u guys then!!

"Bad downpipe" you mean the material they used, bad welded, or smth else? Coz by the look of my dp it seems to be fine pls enlighten me on this part Mike ty

Heist_tub: your dp situation all is good now sir?

[heist_tub]

Yep all I had to do was turn them to be in correct position not touching any part of the wastegate and problem solved. Couldn't for the life of me figure it out, kept thinking it was a leak or bad O2 sensors but was just the clamp haha. Easy fix

[AntonioZ]

Yes definitely look into the clamps. I did mine a couple weeks ago and put them on at first and they were hitting the wastegate actuators. Adjusted the clamps them and now everything is fine.

[ShocknAwe]

Totally forgot about the clamps. That's most likely it. The bolt on them is really easy to get in the way of the WG actuator. I remember wrestling with mine for probably a half hour the first time to make sure it was 100% not in the way of anything.

[BHammzy]

Alright thanks a lot! I'm definitely going to look into that today. At this point it just makes the most sense for that to be the cause of the problem. I've checked basically everything else up until this point so once I get it on the lift today I'm going to investigate that and hopefully that's all it is. It's been driving me crazy for the last 2 weeks so I can't go much longer or I'll go bald from ripping out my hair

[Goodmorning]

Getting my car look at right now. Will update for results! (Fingers crossed)

Updated!! Car is now fixed(readjust the pipe&V clamp). It pulled stronger than ever. Happy ending

[crankestein]

Cool deal you got issued fixed.

Appreciate posting back with findings.

[Stewy_604]

Glad you got it fixed...always better when its something simple.

[HyeWarrior]

Lmao sub'd for future

[SMartinR]

This post literally saved my from a heart attack. Thank you SO MUCH!
Got the downpipes installed and both, mixed sensors and clamps were the issues.
Amazing how I can even listen to the turbos working now!