SAI Delete - Research so far...

[topher]

there's actually more chance of it failing if you clear the fault right before an emissions test as your fuel trims will get reset which could put the lambda readings out of whack while the ECU re-adjusts the fuelling. Shouldn't be a problem if the car is leak-free and air tight though. Some testers will put an advisory down for EML but it's not a fail... yet!

[OSR]

LR5V - this is exactly what I was now thinking of doing, I don't mind the CEL being on for the remainder of the year but I'm a lot happier now I know I can get rid and it won't instantly return come test time.

I suppose the only danger is if the CEL needed to come on for a legit reason i guess you wouldn't know? Having said that we're all running various tune of cars/maps/mods so I'm comfortable I'd know something was up before the CEL came on in any case.

Topher - I thought any dash lights that didn't go out after initial bulb check with ignition on was an MOT fail?

[lemski]

Eml is advisory. The rest have to go out. Strange why they never changed the rules to iclude eml but im sure they will in time to come

[LR5V]

Wasn't aware the fuel trim would change, but I have done this for the last 2 mot's, first with standard cat second with a used sport cat
-I was more tense about the 2nd with the unknown cat, but it still passed.

[OSR]

^Good to know, I'm running a Milltek sports cat so should be OK as it just passed so I know the cat is capable come next MOT time now I've fully removed the SAI system.

Update on the CEL - came on after about 36miles and around 10 engine starts or thereabouts.

Also I have a question - been out this morning and removed the combo valve and all the hard pipes etc and I now have an unconnected vacuum line that runs from one of the solenoid valves under the inlet mani and used to connect to a tiny hardline that fed straight into the combo valve. What/where should I connect this to?

Also I have an open ended line that comes from the evap system and used to go straight to the TIP via another one of those hardlines, I've plugged the end that goes into the TIP but not sure what to do with this one as I've not removed (and unsure if I will) the evap system.

Any help appreciated!

***EDIT***

Edit to the above, after looking at the colour coded system diagram below (thanks to a google search, noting that this is the same diagram linked to on Vortex), my random vacuum line is actually for the N112 valve, which of course now serves no purpose. I understand my option here is to simply remove all vacuum hoses, cap off the inlet mani (as I've already bypassed the N249 so it doesn't get its vacuum feed from here), and leave the valve plugged in to prevent the ECU logging a code. I can remove the valve altogether but need to fit a 330ohm10W resistor?

That leaves me with one open ended vacuum hose, which is the one for the EVAP system that comes from the throttle body/charcoal canister into the hard pipe that runs along the fuel rail. It is at the end of this hard pipe I have removed the short section of hose that used to connect it into the hard lines that form part of the whole combi-valve assembly.

I note that this section of the EVAP system is past a one-way check valve, so it shouldn't cause any issues as it is, but I guess it's putting some fumes out so am I best dropping a length of vacuum down underneath car for the time being until I get around the deleting my EVAP system?

[LR5V]

Just cap off the EVAP connections at the throttle body & the TIP and delete all the system.

This is what I did to the systems when I did mine-
Green  -Bin
Blue -Bin
Red -Bin
Yellow - can be rationalised, I deleted the vacuum reservoir & redid the pipework & deleted the N249
Pink - can also be rationalised too, mine just runs form inlet to brake servo.
Cyan (light blue) - the engine breather system can be prone to splitting, either replace with silicone (I used Creation Motorsport ones) or re-jig the the pipes to run a catch can.

I sourced a engine kit of silicone hoses - just ebay 1.8t silicone kit and plenty will show up. The Mr.Silicone kit was good.
The opening left by the SAI pipe on the filter box lid can be capped by a screw on drinks bottle lid siliconed into place or if you can get one the Diesel filter lid is a straight swap with no SAI hose hole.

[OSR]

Cheers bud - makes sense. Think I have everything sorted apart from removing the EVAP now, I previously bypassed the N249 and did all the vacuum hosing whilst I was there and run the brake servo directly from the inlet etc.

Do you run a resistor for the EVAP system at all?

[Dalo Harkin]

Just cap off the EVAP connections at the throttle body & the TIP and delete all the system.

This is what I did to the systems when I did mine-
Green  -Bin
Blue -Bin
Red -Bin
Yellow - can be rationalised, I deleted the vacuum reservoir & redid the pipework & deleted the N249
Pink - can also be rationalised too, mine just runs form inlet to brake servo.
Cyan (light blue) - the engine breather system can be prone to splitting, either replace with silicone (I used Creation Motorsport ones) or re-jig the the pipes to run a catch can.

I sourced a engine kit of silicone hoses - just ebay 1.8t silicone kit and plenty will show up. The Mr.Silicone kit was good.
The opening left by the SAI pipe on the filter box lid can be capped by a screw on drinks bottle lid siliconed into place or if you can get one the Diesel filter lid is a straight swap with no SAI hose hole.

Pretty much what I did, get rid of everything and either block it off, put a resistor in or replace it with silicone
I capped the inlet on the TB and the one under the inlet manifold, capped one of the lower ones off the TIP.
Removed the Carbon filter and fitted a resistor, removed the N249 and N112 fitted resistors and removed the SAI and all pipework and fitted a catch can.
If you PM me your mobile I will send you what pics I can on whatsapp and you will have a better idea

[OSR]

Thanks for all the helpful replies so far guys - I've been away/ busy with work so not much time to tinker with the car, however I have finally got a garage ( ) so I've been on clay bar duty for the last couple of weekends whilst the Scottish weather held out and cleared the garage for storage over winter.

Anyway, back to the SAI stuff - I still have the EVAP system to remove, but ordered a pack of 5 330Ohm10W resistors off eBay for £3, they took forever to arrive (from China via Malta?!) and I severely hope they don't set alight  My mate does a lot of wiring looms for rally cars so I'm hoping he can source me the female version of the vag connectors via his suppliers and I can make some plug and play resistor bits to finish the loom off neatly. Very rare I'll ever put all of that junk back into play but saves me hacking bits of loom apart which feels a bit much especially as it's all generally hidden from view.

I've done a few short journeys and no EML back on post SAI removal, so as someone mentioned above it will randomly show after a few days/weeks - it definitely isn't related to a specific mileage, engine start-ups, or running time so I assume it must count every time it want to run the SAI system and kicks up a fault after x number of unsuccessful tries.

The only thing I'm cosmetically unsure about is I'd quite like to remove the N249 metal plate from the inlet mani but if this comes off the dipstick tube has nowhere to locate to and also I can't fit the lower engine cover as the mounts are on the metal plate. Pretty minor one but I quite like the engine covers - it's a fairly ugly engine IMO with that valve cover and coil packs pocking out, even when people do powder coat the valve cover 

[lemski]

Dipstick will be fine withough that plate, just make sure the dipstick tube isnt already broke.
I personally prefere the engine cover on but dont like the little cover around the inlet