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The correct way to do an N249 bypass the full guide


Active Member
Jul 27, 2011
Followed this guide 2 days ago. Everything's been superb. This morning on way to work an EML has appeared what could it be ? Going to reset it tonight and see if it appears again. I did notice that on start up that it makes a weird noise like its hesitating to start ??


Active Member
Aug 2, 2012
In a shed
I'm going to do the bypass on my AUQ tomorrow. I'll try to get pictures aswell.

In picture 13, it says:

"remove all pipe of the resistors"

I'm assuming this means once you remove the pipes only the resistors remain on the pieces you removed them from. So I don't need to purchase any resistors?

I'll also be using the T piece to include the SAI? braided hose to prevent the fault code.


mc funbot

its a beast its got boost
Jan 29, 2010
sunny kettering
yeah thats the 1 mate. T in to sai stops that being at fault. yes remove all the vac off the n249 plugs and the put it back on. that way the n249 works as a resister and can do its thing. any probs just ask.


onvi yellow cupra r
Apr 12, 2011
hey guys and gals after having a slight debate over the way to do an n249 bypass
this is how i would do it,i like to know your views on it.i see alot of people only doing half a job.a random guy with a 1.8t leon agreed to let me do this.it had a cat back exhaust an a air filter.this took me 25 mins to do.that was with taking photos and telling the lad what i was doing..

lets get started this is simple and a great mod ive done it to all my 1.8t cars from standard mk4 golfs to my mk3 ibiza at 340bhp

tools needed

this is what you will start with

this is what you will have removed

your work is good now reward your self with a beer and a pat on the back!

this is all the rubbish that you should have removed..

i hope this helps you guys an ive never had any problems just improve ments not engin lights on..

Hi mate so to do the n211 and n249 by pass but keep the sai pump I just go from inlet to dv then t in to dv to the pipe you blocked. Leave every thing pluged in and no faults should pop on vag com


onvi yellow cupra r
Apr 12, 2011
Cheers mate ive been getting the code on vagcom for pressure drop between turbo and throttle body so gonna try this as it says it could be faulty n249


Active Member
Mar 12, 2016
Followed this guide on my Cupra 20vt 180 AUQ car boosts stronger and sounds great!
Been done for approx 1-2 weeks now and had the dreaded eml appear but not bothered.. Going to sack off the whole sai system next.

Sorry to bump old thread btw
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