mc funbot

The correct way to do an N249 bypass the full guide

Mk1 banana

Active Member
Dec 16, 2012
334
1
(Not so) Sunny Hastings
Cheers mate :), I know its miles away, ill get it done once me resistors arrive...

New inlet mani fitted (was a bit of a bar steward), n112+n249 now properly bypassed, without upsetting fpr...:D runs a lot better now mate, quite responsive now too, brilliant guide, I can get you some piccys soon, but it looks a mess at the mo, I've still got a few loose (un used) hoses flapping about, and I'm gonna chuck the sensors completely, along with sai first.
 

SEATSAMBO

Active Member
Feb 18, 2013
50
0
What's happened to posts #20 to #40 then lads??! I'm after a good guide to remove the SAI system as I'm getting a p4011 fault code and can't work out what's wrong with it!! Will removing the SAI get rid of any incorrect SAI system flow fault issues?
 

Mk1 banana

Active Member
Dec 16, 2012
334
1
(Not so) Sunny Hastings
Yes it can remove the code. The Sai pump splits where both parts join an that's what normally gives you the fault. I am going to do an guide when i find a car that had not been don't yet.

If I get time mate, I can take the pics of what I do, (while doing it) when I kick mine out, ill let you do the editing and instruction thing though ;)
I'm not certain tho, as I normally rush everything in my lunch breaks...
 

mj0251

Guest
good guide done it to my car but bout a month later engine management light came on came up with code 16750 i think it was any ideas why?
 

Mk1 banana

Active Member
Dec 16, 2012
334
1
(Not so) Sunny Hastings
good guide done it to my car but bout a month later engine management light came on came up with code 16750 i think it was any ideas why?

Don't remember the code, but more than likely sai fault, perhaps :
secondary air injection, incorrect flow

Mine did this, they say; 330 ohm 10 watt resistors cure this, but DON'T. Order them from hongkong lol, I did this and we still have issues (intermittently)
Try a UK supplier.
 

mj0251

Guest
think that's exactly what it was mate cleared it with handheld scanner see if it pops up again.
okay cheers, where am i putting these resistors? (not to sound completely stupid) :D
 

Mk1 banana

Active Member
Dec 16, 2012
334
1
(Not so) Sunny Hastings
Does it judder/ jerk with light throttle changes, like full to 3/4 throttle?
Was curious as mine has started doing it intermittently when I did the bypass, then almost constant after remap...

The two plugs on the sensors, that were removed on the bracket,

When you removed two Allen bolts from Inlet manifold, and pulled the metal bracket out, with the pipes/hoses and two sensors, (which would have been unplugged) either find a way of securing the resistors to the existing plugs (one each) or cut plug off, and solder the resistors between the two wires (from each plug) it shouldn't cause any harm either way, mine still pulls like a train, and my dyno print out was when the fault was present, and amd weren't too worried...
 

davezx

Active Member
Feb 19, 2013
86
0
doncaster
Think i will give this a go tommorow. Brilliant write up and pics. You should do a haynes manual for the leon,lol

Sent from my XT615 using Tapatalk 2
 

mc funbot

its a beast its got boost
Jan 29, 2010
1,473
4
sunny kettering
www.seatcupra.net
Hahah glad you got on ok with it. There is a Sai guide soon to follow I'm just looking for a Leon to do it on. I've not bothered with resistors as always had then plugged back to the n249. You can get faults from resistors now and then some do and some don't. Depends in the car.
 

Mk1 banana

Active Member
Dec 16, 2012
334
1
(Not so) Sunny Hastings
Could someone please do me a little favour... If someone gets time, would they please have a peek under the bonnet, and let me know which colour wire goes on the left and which one right, for the n112 valve, I cut the plug, put in a resistor and it didn't work out, so reinstalled the n112 on its own, but can't find the old plug to configure.

The 112 is on left as you look at the front of car, with two vacuum hoses.

(Use the metal spring clip as a reference for top)

Cheers guys:)
 

James D1

Pre-facelift
Aug 2, 2012
255
0
Essex, Uk
used your guide and it was very clear and has helped me to achieve mine and a friends bypasses.

instantly noticed the hesitation from the turbo had disapeared after bypass, would recomend it!
 

Adjay

Active Member
Sep 5, 2011
393
1
Donegal,ireland
I'm at the moment removing the sai. Does the egr pump piping all come off come off also cos onto the pipe is the evap and I don't want to take it off yet. Does my forge blanking plate go on the side of the engine or flat after the valve comes off. Do I leave the hard pipes in.
 
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