DIY - B6 1.8t - Vacuum line and Check Valve removal/simplification

[Charles.waite]

^^ What year is your A4?

[Kevboarder]

its a 2005 1.8t ultrasport, it seems to be a little of a 2004 and a little of a 2005 even though its after the vin split

[AutoUnionLov3r]

Anyone do this simplification and have fluctuations in wastegate response after deleting the N112? I'm not too happy with my part throttle response as it feels like my WG is been activated more than necessary. At part throttle I'll let off the gas, get a slight flutter, then it feels as if my car wants to squeeze out about 2 more psi as I hold my throttle about 1/4 way down. Is this from the N112 delete or possibly something else?


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[caspar]

Hi,

I've a little question. I can't undrestand why there is no check valve (after the simplification) between the brake booster and the manifold?

[tehbry]

I really want to do this as I just did the N249 delete today but none of the pictures work :(

I'm definitely not going to attempt this without the pictures, anyway I can get them to work?

[tehbry]

I really want to do this as I just did the N249 delete today but none of the pictures work :(

I'm definitely not going to attempt this without the pictures, anyway I can get them to work?

pweaaaaase

[B3rgersen]

someone that have the measurements for the blockoff plate? like this http://www.uspmotorsports.com/Integr...T-Engines.html

[K04-B6]

So if I read this correctly, It's better to run the DV off the Intake? So I should be able to just loop the N249 valve and leave it plugged and run the DV off the intake and I can also do the crank breather and valve cover breather mod while im there and shouldn't have any CEL? I have the APR system with 4 stages and k04 so I don't know if I the readiness is already done if i was to remove the SAI. Can anybody shed some light for me on this please?

Thank you

[Timtheguru]

Retain the N249

[Charles.waite]

Retain the N249

I bypassed mine and notices zero difference. I did it to try and diagnose a weird boost hesitation that it did literally nothing for. I've been too lazy/don't car to hook it back in again though.

[K04-B6]

Also, If I run some line from the intake to the DV, What size should I go with? because the original line running from the intake to the N249 is smaller then the line running from the N249 to the DV.

[Charles.waite]

Also, If I run some line from the intake to the DV, What size should I go with? because the original line running from the intake to the N249 is smaller then the line running from the N249 to the DV.

They should all move the same size. 4mm. That's what I used on everything.

[K04-B6]

They should all move the same size. 4mm. That's what I used on everything.

Oh ok perfect, Thanks for the help! If I have time this weekend I will give this a try

[Timtheguru]

I bypassed mine and notices zero difference. I did it to try and diagnose a weird boost hesitation that it did literally nothing for. I've been too lazy/don't car to hook it back in again though.

You wouldn't but your turbo would, I would post a link, but it goes to the B5S4 forum... and people don't like it when I do that. Even though we have the same discussion about the N249, as it functions the same way for the B5S4..

[old guy]

For what its worth here's my experience with the N249: Clicky click My advice is to leave it hooked up.

[Timtheguru]

Ah, what the hell. We even have graphs and shit.

N249-delete-Why-you-should-not-do-it

[old guy]

Great link Tim! It confirms my measured mileage decrease with it disconnected. After reading that information I can see how disconnecting the N249 can take away some of the smoothness of operation and cause a bit of increased abruptness when on and off throttle. The increased abruptness can be interpreted as an increase in responsiveness whereas it is really more of a decrease in smoothing of the boost transition.

[Timtheguru]

Glad to be of service!

[K04-B6]

Sorry if this has already been answered but i didn't want to read through all these pages and find out this wasn't asked. With doing this mod will the crankcase breather still work properly since there is no longer a PRV valve? And also to prevent of having the SAI pump CEL light come on i would have to leave it plugged but what if I was to do a closed loop system with that? As in just run a line from the inlet to the outet straight on the pump.

[Charles.waite]

Ah, what the hell. We even have graphs and shit.

N249-delete-Why-you-should-not-do-it

Great link Tim! It confirms my measured mileage decrease with it disconnected. After reading that information I can see how disconnecting the N249 can take away some of the smoothness of operation and cause a bit of increased abruptness when on and off throttle. The increased abruptness can be interpreted as an increase in responsiveness whereas it is really more of a decrease in smoothing of the boost transition.

Never saw this until now. VEEEERY interesting. Considering I looped my N249 thinking it would solve my boost stutter, only to find out the real culprit was an Air filter with 96k on it , I might just re-instate my n249. I didn't really notice much of a difference after I looped it, but I've been mulling over returning it to stock for a week or two now that I've solved my intake restriction. Might have to man up and just reconnect it soon assuming I have enough vacuum hose to run the proper lines...

[freeloader700]

Wow did not know that about the N249. I looped mine 8 months ago. I did feel a little more response or that the "throttle felt more connected" like OG said. I am getting 18-20mpg 50/50 city highway. Maybe this will help it out. I am sure though that my aggressive driving has a part to do with the mpg

Looks like I will have to switch it back. Good info

[K04-B6]

Sorry if this has already been answered but i didn't want to read through all these pages and find out this wasn't asked. With doing this mod will the crankcase breather still work properly since there is no longer a PRV valve? And also to prevent of having the SAI pump CEL light come on i would have to leave it plugged but what if I was to do a closed loop system with that? As in just run a line from the inlet to the outet straight on the pump.

Anybody?

[Fast4esT]

When I bought my car all this stuff was deleted, the n249 valve is there and plugged into the wiring, but no vac lines are connected to it. How can I and what else would I need if I wanted to hook it back up?

[AutoUnionLov3r]

When I bought my car all this stuff was deleted, the n249 valve is there and plugged into the wiring, but no vac lines are connected to it. How can I and what else would I need if I wanted to hook it back up?

Read, figure out your exact hose configuration for your year engine and start ordering parts. Follow A4Darkness' post on "Engine Strengthening" to familiarize yourself with the needed hardware and shop smart.


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[old guy]

When I bought my car all this stuff was deleted, the n249 valve is there and plugged into the wiring, but no vac lines are connected to it. How can I and what else would I need if I wanted to hook it back up?

Pretty straight forward. The line that currently runs from the front corner of the intake manifold to the DV needs to be rerouted to the N249. Then run a line from the N249 to the DV. Done. Here is a visual that may help: Clicky click

[old guy]

Sorry if this has already been answered but i didn't want to read through all these pages and find out this wasn't asked. With doing this mod will the crankcase breather still work properly since there is no longer a PRV valve? And also to prevent of having the SAI pump CEL light come on i would have to leave it plugged but what if I was to do a closed loop system with that? As in just run a line from the inlet to the outet straight on the pump.

You really do need to read through "all these pages" to get your answer. If you just start pulling out stuff willy nilly with no understanding of their functions you will be back posting "Why is my engine all f***ed up and misbehaving??????? Why do i have a CEL?????? Why does my idle go up and down?????

This thread might help a little: Clicky click. Once you understand the functions of the various components you can make an educated decision as to what you would like to eliminate and what you need to retain.

And to answer your questions:
"Will the crankcase breather still work properly since there is no longer a PRV valve?" No.

"And also to prevent of having the SAI pump CEL light come on i would have to leave it plugged but what if I was to do a closed loop system with that? As in just run a line from the inlet to the outet straight on the pump." No.


Cheers!

[K04-B6]

You really do need to read through "all these pages" to get your answer. If you just start pulling out stuff willy nilly with no understanding of their functions you will be back posting "Why is my engine all f***ed up and misbehaving??????? Why do i have a CEL?????? Why does my idle go up and down?????

This thread might help a little: Clicky click. Once you understand the functions of the various components you can make an educated decision as to what you would like to eliminate and what you need to retain.

And to answer your questions:
"Will the crankcase breather still work properly since there is no longer a PRV valve?" No.

"And also to prevent of having the SAI pump CEL light come on i would have to leave it plugged but what if I was to do a closed loop system with that? As in just run a line from the inlet to the outet straight on the pump." No.


Cheers!

Thanks for the help! I am new to Audi so I'm still learning abit about these motors. I have abit of mechanical knowledge since I do all my own work and used to work in a shop. I thought that this DIY was to remove all the useless vacuum lines and wouldn't cause any harm to the motor. I'm aware of what the SAI pump's function is but alot of people say it's useless since it only comes on for 90 seconds on cold starts.

[texasboy21]

Thanks for the help! I am new to Audi so I'm still learning abit about these motors. I have abit of mechanical knowledge since I do all my own work and used to work in a shop. I thought that this DIY was to remove all the useless vacuum lines and wouldn't cause any harm to the motor. I'm aware of what the SAI pump's function is but alot of people say it's useless since it only comes on for 90 seconds on cold starts.

Audi did not put any useless line under the hood. They are have a purpose.

[AutoUnionLov3r]

The SAI function is to pre-heat your catalyst to operate at optimal temperature for the sake of not ruining your secondary o2 sensor. Anyone can correct me if I'm wrong here but that is my understanding of the SAI pump. Do yourself a favor and keep all the vacuum lines and check valves. You'll thank us later for saved headaches.


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[old guy]

The SAI pump works in conjunction with the 22° of intake cam advance to help get the catalytic converter up to temperature faster thus reducing emissions and increasing the longevity of the cat. It has no performance implications other than what I just listed. If you are running a test pipe the SAI system becomes unnecessary.

[K04-B6]

Well I guess I'll leave everything alone then if it's only going to cause problems down the road, I'm planning on going with a 3" HFC and down pipe from Unitronics this summer. I bought the car last spring and it already had the fully loaded Ecu from APR, with injector and k04 so I wasn't sure what this mod could of caused.

I appreciate all the input

[AutoUnionLov3r]

A whole lot of good reading to be done here >http://www.audizine.com/forum/showth...-by-a4darkness


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[Red Gumball]

Just completed this whole procedure without any complications. Drove just fine for a couple days and then noticed a CEL. Thought nothing of it since removed SAI. Then I started getting stutters out of the car under acceleration and only when at a warm temp. Checked the CEL and got a p0441 purge valve emissions code. Cleared the code but am still getting the stutters. I will say that instead of looping the hose on the n249 I just plugged all the nipples on both the n249 and n112. Would that be causing the issue?


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[texasboy21]

Just completed this whole procedure without any complications. Drove just fine for a couple days and then noticed a CEL. Thought nothing of it since removed SAI. Then I started getting stutters out of the car under acceleration and only when at a warm temp. Checked the CEL and got a p0441 purge valve emissions code. Cleared the code but am still getting the stutters. I will say that instead of looping the hose on the n249 I just plugged all the nipples on both the n249 and n112. Would that be causing the issue?


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Is your N80 still hooked up?

[Red Gumball]

Is your N80 still hooked up?

Yes still hooked up and venting to atmosphere. I followed the DIY step by step.


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[Charles.waite]

Just completed this whole procedure without any complications. Drove just fine for a couple days and then noticed a CEL. Thought nothing of it since removed SAI. Then I started getting stutters out of the car under acceleration and only when at a warm temp. Checked the CEL and got a p0441 purge valve emissions code. Cleared the code but am still getting the stutters. I will say that instead of looping the hose on the n249 I just plugged all the nipples on both the n249 and n112. Would that be causing the issue?


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Hook your n80 back up properly. It's an integral part of the fuelling.


Posted from my iPhone. Any misspellings are Siri's fault.

[texasboy21]

Yes still hooked up and venting to atmosphere. I followed the DIY step by step.


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Connect it back to your TIP and see if that fixes your problem.

Yet ANOTHER 'I took stuff out now I have a CEL' post. When will people get it?

[Red Gumball]

Connect it back to your TIP and see if that fixes your problem.

Yet ANOTHER 'I took stuff out now I have a CEL' post. When will people get it?

You must of not of read my original post. I know I will have a CEL. that I don't care about. READ my first post and you will see what I'm trying to figure out.


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[Red Gumball]

Hook your n80 back up properly. It's an integral part of the fuelling.


Posted from my iPhone. Any misspellings are Siri's fault.

1) But I still am confused as to what i do with the EVAP purge valve. Doesnt that release gas-fume build up from the tank? That is obviously necessary.

1) EVAP purge valve needs to stay connected to the line from the tank, the line that comes from the passenger fenderwell. Everything between the solenoid and the motor can be removed. It needs to stay plugged in and connected to the tank feed line in order to bleed off any fume or pressure buildup. if there is gas pressure in the tank it will vent on it's own. that's how equalizing pressures work. Taken from post #14


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[texasboy21]

1) But I still am confused as to what i do with the EVAP purge valve. Doesnt that release gas-fume build up from the tank? That is obviously necessary.

The N80 needs to be connected to the TIP and intake manifold with a check valve inline. See my (older) pic below. Notice the white T running from the N80 to the TIP and back near the firewall. There is a good change your stumbling is from not having it connected properly.