mc funbot

The correct way to do an N249 bypass the full guide

Stepup

Active Member
Oct 12, 2013
26
0
I assume its to do with efficiency etc. I'm not sure if its placebo but the car seems to feel better going through gears now whereas it was laggy when shifting up before.
 

mc funbot

its a beast its got boost
Jan 29, 2010
1,473
4
sunny kettering
www.seatcupra.net
Removing the n249 just helps pick up. I notice it more as its on a track car so going through the gears it open an snapping shut is whats needed the little black box is an air chamber. They dont always fill quick enough an can make for jurking some times.

as for bam guide they are doing what im doing. But leaving all the crap on top not so sure about they are the same as the tt set up all on top of the engine.ive done a new an removed the pipes an just left the resister an that was ok from the feed back of the customer.

Its nice to see my guide working an people looking in to stuff aswell. I know this has done people well on other places to.
 

mc funbot

its a beast its got boost
Jan 29, 2010
1,473
4
sunny kettering
www.seatcupra.net
Removing the n249 just helps pick up. I notice it more as its on a track car so going through the gears it open an snapping shut is whats needed the little black box is an air chamber. They dont always fill quick enough an can make for jurking some times.

as for bam guide they are doing what im doing. But leaving all the crap on top not so sure about they are the same as the tt set up all on top of the engine.ive done a new an removed the pipes an just left the resister an that was ok from the feed back of the customer.

Its nice to see my guide working an people looking in to stuff aswell. I know this has done people well on other places to.
 

nathan_20vt

Active Member
Mar 30, 2013
365
0
Kings Lynn, Norfolk
Ive seen a few people said this my gti never did this. The one you block of with a bolt if I remember right thats to the sai.. T your dv to this aswell see how that goes an holla back

Finally got round to doing what you told me to do the other day. Since 't'ing the sai hose into the DV line the sai is a lot quieter on start up (sounded like a jet plane before). After running around a couple of day while I waiting to get my EML turned off the light turned off its self and has not come on since.
Anybody with the code after doing this bypass should do this! My engine code is AUQ btw. Can get some pictures if anybody is unsure. Thanks for your help mc funbot! :D
 

demonskills

Guest
help please

Hi buddy in pic 20 where you take the plate off and remove all the pipes..what is that called?? I have a seat leon 1.8t 20v with the n249 bypass but the plate you have taken off is missing and the two connectors are not plugged in there just hagging there!! when I hit 3.5/4 rpm the car holds back and stutters, when this happens I can hear a valve breaking down surcharge sound could this be the n75 valve breaking down?? iv only had the car a few weeks and it was running fine but since the car started playing up it feels like its over boosting and running rich, iv replaced the MAF sensor, spark plugs, coil packs and its running better but still stuttering and holding back at 3.5/4 rpm had it on computer yesterday here is the outcome.

fault code 17840 secondary air inlet valve n112 open circuit

fault code 17695 recirc vavle for turbo n249 short circ. open circ. voltage supply to low

fault code 17968 (p1560) maximum engine speed exceeded
sporadic fault

fault code 17608 (p1200) recirculating valve for turbo charger n249 mechanical malfunction.

I take it the n75 cant cope with the boost?? am i right i need a new n75 valve?? or is it becasue of the two connectors that or not connected??

I have a seat leon 1.8t 20v 2002

many thanks
 

mc funbot

its a beast its got boost
Jan 29, 2010
1,473
4
sunny kettering
www.seatcupra.net
Post a photo up of the engine bay for me to take a look at. Not having them plugged shouldnt make it drive different.n75 should handle boost if you over boost will go in to limp mode. Have you cleared all the fault codes an see what comes back after a few days? Make sure you have no split pipes or open pipe work. Check the pipe under the inlet manifold in the middle they are commen to split. .
 

demonskills

Guest
hi mate and thanks for the reply, yes I have checked all over for splits but everything is ok, the same fault codes keep popping up.
fault code 17840 secondary air inlet valve n112 open circuit

fault code 17695 recirc vavle for turbo n249 short circ. open circ. voltage supply to low

fault code 17968 (p1560) maximum engine speed exceeded
sporadic fault

fault code 17608 (p1200) recirculating valve for turbo charger n249 mechanical malfunction.

but as I put my foot down the car pulls how it should but then it holds back and starts to stutter I can hear a loud ticking nose like a valve is shorting out its getting very annoying now grrrrrr!!!!

from start up when cold it jerks about al over the place when driving through gears not even hitting boost and turbo, when it gets warm it will either go into limp mode or be ok or start stuttering and surging its so frustrating.

Because im new it wont let me upload pics yet, do you have an email i can send you the pics many thanks.
 

demonskills

Guest
Im in bedfordshire mate where you based?? cheers mate I appreciate your help, I wil send these pics to your email now mc funbot :)
 

Ryanisadipper

Guest
Do you just need one pipe running straight through once you removed everything else? So I only need to buy one extra pipe?


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Ryanisadipper

Guest
Sweet thanks got the pipe gunna try it on the weekend


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rallychief

Active Member
Oct 13, 2008
101
0
I live in South Devon
hi just done the N249 bypass, because I had a VCDS fault saying N249 mechanical failure, have reset fault code, and driven car for a couple of days, but the fault code has returned, should I be getting the fault code with it removed, the N249 plate has been replaced and both plugs reconnected, as didn't want to play with resistors.


Cheers Chris
 

rallychief

Active Member
Oct 13, 2008
101
0
I live in South Devon
Hi. all pipes taken off N 249 block, I only have one pipe blocked with Allen bolt though, should their be more ? did the bypass as I had major hesitation, which I thought might be being caused by the n249 fault, the hesitation is improved, but car seems to have a little less power than before.

Whilst we were doing it, i noticed a bad split in Y shaped hose to PCV valve, repaired for the minute, PCV delete next job, but can't find the guide for it, or n75 valve.

Cheers Chris
 
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DannyJigg

Active Member
Jul 4, 2013
237
1
Southend, Essex
Seat fitted it as a safety measure to prevent overboost, the reason people (we) remove it all is that components tend to degrade/fail over time and the system becomes inefficient/faulty. The options are; remove it or replace the parts (which costs more and means they will only fail again later). Remember the old saying; keep it simple, stupid! Applies here.
 

Longy82

Active Member
Jan 9, 2014
372
0
West yorkshire
Hi there I just bought an 04 plate cupra 1.8t and keep getting the 17705/16795 codes so I posted a picture on here as I had all sorts ov pipes missing ect a top bloke said it looks like the bypass thing so I was just wondering maybe it could be that what is bringing my codes up if not done propley I only ask as I have just seen one done but they teed into the fuel regulator but yours doesn't? But after looking at mine and what you did mine looks the same so maybe it's not that whats bringing my codes up? Thanks matt
 
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