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SAI, N249 and N112 Removal Guide

Discussion in 'Mk1 Leon FAQ's (1M) 2000-2006' started by Mo Arif, Apr 3, 2011.

  1. Mo Arif

    Mo Arif V.A.G Planet

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    Ok I've found a pretty good guide on the net (not mine) but here it is, may be helpful to a lot of us!:

    SAI, N249 and N112 Removal Part 1

    Jack car up and place on axle stands.
    Working from underneath Remove bottom engine shield (4 torx screws)

    [​IMG]

    [​IMG]

    Next unplug SAI sensor

    [​IMG]

    [​IMG]

    Remove the 3 x 10mm nuts holding SAI to Bracket(note you won’t be able to remove the SAI yet, not enough space) Also you can remove the 2 plastic hoses to the SAI to get better space if needed.

    [​IMG]

    You will need to remove 3 x allen bolts holding bracket to engine. Top bolt pictured is tough to get to. But I found it easier from above engine using a small ext bar onto allen socket and then a knuckle joint and another extension bar to the racket.

    [​IMG]

    The lower 2 bolts not really a problem to get to (pic shows where they were)
    Now you can unclips the input and output plastic hoses from the SAI and then remove the SAI from the car.

    [​IMG]

    Both SAI and mounting bracket removed.

    [​IMG]

    Next was to fit the resistors to the wiring loom to fool ECU the removed parts are still there. Pic of what they look like crimped and ready to fit.


    [​IMG]

    Fitted to the wiring loom.

    [​IMG]
     
  2. Mo Arif

    Mo Arif V.A.G Planet

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    Taped up and cable tied to the main loom

    [​IMG]

    Car can be lowered down onto floor now as the rest of the work is from above.

    Remove the 2 engine covers (if you have both fitted) by twisting the plastic screws 90’ (not pictured)

    Now you can remove the 2 x SAI plastic hosing from the car by removing the 2 x 10mm nuts holding the top hose in place pictured.

    [​IMG]

    I also removed the 2 x 10mm bolts holding metal bracket in place to the Inlet manifold.
    (to get to the hoses and sensors underneath)

    [​IMG]

    Turn the metal bracket over (being careful not to pull at any cables or hoses)
    Unplug the N249 and the N112 sensors. Example of one shown

    [​IMG]

    Remove the 10mm nut holding the other SAI plastic hose to the bracket and remove the hose.

    If you have standard airbox remove the SAI hose from the side of the airbox ( I have a CAI kit so just needed to cut cable tie holding the hose in place and remove that hose.

    [​IMG]

    Unclip the other hose from the EGR valve and you can remove the 2 hoses from the car.
    [​IMG]

    Next you need to undo the 2 x allen bolts holding the temp sensor coolant hose asm to to be able to get to the EGR bolts. You will loose 500ml of coolant.

    [​IMG]

    Push the coolant hose to one side. Unplug EGR sensor, pull off the small rubber hose to the back of the EGR valve, then undo the 3 x Allen bolt holding the EGR in place.

    [​IMG]
     
  3. Mo Arif

    Mo Arif V.A.G Planet

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    SAI, N249 and N112 Removal Part 2

    Remove the EGR

    [​IMG]

    The hole in the black where the EGR valve was will need to have a blanking plate fitted

    [​IMG]

    This is where the Forge blank comes in that has a rubber seal on one side.

    [​IMG]

    [​IMG]

    Forge blank fitted in place with the 2 allen bolts supplied

    [​IMG]

    That is the SAI removed. Next the N249 and N112.
     
  4. Mo Arif

    Mo Arif V.A.G Planet

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    SAI, N249 and N112 Removal Part 3

    Start by removing the Metal bracket holding the N249 and N112 units. To do this you will need to unclip the 3 hoses that connect to the metal hoses running round the side on the engine to DV, EGR valve and plastic Vacuum reservoir that side on coil pack no 4.(pictured).

    [​IMG]

    Remove the rubber hose connecting to the inlet manifold(pictured)

    [​IMG]

    Now bracket can be removed.

    [​IMG]

    [​IMG]

    Now you can remove the Vacuum reservoir rubber hose and unit from the engine.

    [​IMG]

    [​IMG]

    Now you can remove the bracket that held the Vacuum reservoir in place.

    [​IMG]

    The original DV hose can be removed.

    [​IMG]

    and replaced with a longer hose that goes from DV to inlet manifold nipple that used to have a hose from the T piece from the N249 valve.

    [​IMG]

    [​IMG]
     
  5. Mo Arif

    Mo Arif V.A.G Planet

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    Now all that is left to do is to locate the wiring sensors that used to be connected to the N112 and N249 and fir inline resistors to them as shown.

    [​IMG]

    [​IMG]

    [​IMG]

    Afterwards admire all the bits you have taken off

    [​IMG]
     
  6. Mo Arif

    Mo Arif V.A.G Planet

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    Hope this helps as I know many of you perhaps would want to do this, I've only done the n249 removal thus far.

    Mo
     
  7. S's Cupra

    S's Cupra Project Tidy up underway

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    This is great info Mo, will give this a go.
     
  8. vwdom

    vwdom Active Member

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    what does this lot do and what is the benefit of removing it :confused:
     
  9. aviaa25

    aviaa25 Active Member

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    nice DIY
    what kind of resistors do you put on the air pump (sai)?
     
  10. LEE69

    LEE69 Stage 2 Revo'd

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    330ohm resistor
     
  11. seatcupramad23

    seatcupramad23 kc4even23

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    great guide mo most helpful one i've seen so far , no it's time to invest in some tools i think
     
  12. cupra-db

    cupra-db Active Member

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    the guy who did my 249 removal left the sensors connected and didnt fit the resistors, is this right as im getting related faults?
     
  13. LEE69

    LEE69 Stage 2 Revo'd

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    Yes as the sensors are not ermmmm sensing ;)
     
  14. 51mo

    51mo Active Member

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    As mentioned above in a previous post an someone enlighten me as to what removing all the above achieves please?
     
  15. auq

    auq Avoiding Potholes!

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    The 2 valves just control the BPV and SAI. So if you deleted the SAI and ran a hose to the BPV you dont need either of those control valves.

    SAI only comes on while the engine is cold and is really only there for emmissions to add air to the rich exhaust gas and increase the flow.

    BPV By-pass valve
     
  16. seatcupramad23

    seatcupramad23 kc4even23

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    i want to remove sai , and pvc and n249 n112,
     
  17. cupra-barn

    cupra-barn It's all about stealth!

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    That's a really good find there. Cheers
     
  18. Yatsy999

    Yatsy999 Guest

    I know this is an older thread but i need to give this a try, is there no pics for this anymore, or have photobucket lost them?....
     
  19. LEE69

    LEE69 Stage 2 Revo'd

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  20. Mo Arif

    Mo Arif V.A.G Planet

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