need some help on combo valve/SAI issues!!! ( save me $400!!)

[TT Wagon]

ok, this might get a little long but i want to give all details to try and get this solved.

2003 allroad 2.7t

i have been getting 2 codes for SAI insuff. flow bank 1&2. When i first looked into this issue, i noticed the Vacuum line on the driver side combo valve was split right at the metal crimp fitting. so i fixed that best i can( used what i call comression tape, its a silicone type material that compresses as it cures, mean for coolant,and cooler line leaks. non the less, no more leak. cleared codes, but they return. So reading some threads people are saying to check the vacuum lines coming from the 112( ?) valve, and that the SAI pulls fresh air from under the air box. So i pulled the air box, disconnected the MAF so i can remove it all at once, and there is NOTHING under the air box. nothing going into the bottom of the air box. From the 112 valve, i can follow 2 lines, one splits into 2 lines going across the intake, the other goes over the MAF, into the passanger fender and then back towards the CABIN of the car. all these lines look good. Called audi dealer ( tech supervisor is super cool) and asked a bunch of questions. he said try replacing combo valves. parts stores here want $400.... EACH!! i know the air pump is workingas i didnt get the plastic hose connected completly one time and could feel masive air flow.

so i need help. if the SAI doesnt pull air from under the air box.. then where? where does the line going into the fender go to? and is there anything els anyone can think of that would make these code appear?

ontop of all of this, when i removed the maf i forgot to plug it in before starting the car. got CELs as normal, but now my esp and abs lights are on as well.They wernt on when i pulled the car into the garage. Then went to autozone to clear said codes, once i cleared the codes, went to start the car, and it acted like a dead battery. keep in mind car started just fine when i started it to go to autozone. so i got it jumped, drove home no prob. now the car will start, but it act like there isnt enough juice to crank it like normal. i know its getting cold ( in idaho) and batteries die, but how could it be just fine 10 min. before hand, and now not so much.?

Sorry for the long post. just super annoyed right now with the car and would like to get this issue fixed.

if you got this far thanks for reading this novel, and thank you for any input. its much appriciated.

TT

[Wide-66]

Delete the SAI and have it coded out. But if you do need parts i have a box of good combis and the rest of the SAI stuff from deletes I have done.

[TT Wagon]

Delete the SAI and have it coded out. But if you do need parts i have a box of good combis and the rest of the SAI stuff from deletes I have done.

its funny you say this. i was googleing what els to check for,and came across block off plates. and was getting on here to ask about the SAI delete. if i get the block off plates can i literally just tear all that SAI crap out? and how do i code it out. obviously i need vcds but with that aside, what exactly are the steps, codes ect.?. honeslty i have put enough time into trying to fix this, and if its the combo valves, id rather just get rid of it.

[seishuku]

It's not something you can do with VCDS, you have to reflash the computer with modified code that removes the DTCs for SAI (basically, more to it than that).

[Wide-66]

^exactly and it is worth it just for how much room it makes and ease of doing vcgs.

[rollerton]

SAIP doesn't pull air from "under the airbox" - there's a 90* angle pipe that is plugged into the bottom half of the airbox, you can see it right behind the passenger headlight.
Test the Combi valve: SUCK into the vacuum line that's connected to the Combi valve. It should HOLD vacuum, you shouldn't be able to suck air through it. Also, there's a bunch of shitty plastic tubing that needs to be intact, no big holes of cracks or anything. Also, there's a vacuum line that comes from the canister under the ABS module, tucked up almost in the wheel well, drivers side.
Here's my understanding of the SAIP /system: When you start the car cold, the N112 is 'switched' to try and open the Combi valve ports- but at the point of starting the engine there isn't enough vacuum. So Vacuum stored in the canister operates through the N112 instantaneously, until engine vacuum is built up and the N112 'opens' the combi valves and allows the fresh air from the SAIP to blow through the combi valves port and into the exhaust. This causes a lean condition (?) and helps heat up the catylitic converters faster (?). Also it 'dilutes' the exhaust and makes the cold-start emissions "SEEM" better.
But they're not. It's a gimmick.
The SAIP gets it's air from the bottom of the airbox, blows it through some plastic pipes into some metal pipes you'll see near the Combi valves.
Trace all the bullhsit from the SAIP around the engine and make sure no vacuum or air leaks in it.

[seishuku]

Yeah, cold start emissions is about the biggest joke I've ever heard... But if all that's wrong is some hoses, then I would just fix it.
Programming out SAI isn't something just anyone can do, but at least with the 2.7 it's been done.

With my 4.2, I'm pretty well screwed... But at least my SAI works (for now).

[TT Wagon]

Ill look this weekend. But if its not a must, then id prefer to remove it and BURN the SAI system. So if thats what i end up doing how do i reflash the ecu? Send it out what? Cuz im bout done with it and emissions in idaho SUCK! Had a truck that was throwing a CEL due to the tranny, and didnt pass.

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[rollerton]

I've had 6 Audi's and 4 VW's that all had the SAIP system, and the few little problems I have had with it were very simple fixes. Worst one was a Combi valve on my 3.0 A4. Kind of a bitch to replace, but no mystery, very cheap.

[TT Wagon]

Combo valve here is $400 each.

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[TT Wagon]

SAIP doesn't pull air from "under the airbox" - there's a 90* angle pipe that is plugged into the bottom half of the airbox, you can see it right behind the passenger headlight.
Test the Combi valve: SUCK into the vacuum line that's connected to the Combi valve. It should HOLD vacuum, you shouldn't be able to suck air through it. Also, there's a bunch of shitty plastic tubing that needs to be intact, no big holes of cracks or anything. Also, there's a vacuum line that comes from the canister under the ABS module, tucked up almost in the wheel well, drivers side.
Here's my understanding of the SAIP /system: When you start the car cold, the N112 is 'switched' to try and open the Combi valve ports- but at the point of starting the engine there isn't enough vacuum. So Vacuum stored in the canister operates through the N112 instantaneously, until engine vacuum is built up and the N112 'opens' the combi valves and allows the fresh air from the SAIP to blow through the combi valves port and into the exhaust. This causes a lean condition (?) and helps heat up the catylitic converters faster (?). Also it 'dilutes' the exhaust and makes the cold-start emissions "SEEM" better.
But they're not. It's a gimmick.
The SAIP gets it's air from the bottom of the airbox, blows it through some plastic pipes into some metal pipes you'll see near the Combi valves.
Trace all the bullhsit from the SAIP around the engine and make sure no vacuum or air leaks in it.

There is nothing on the bottom of the air box.i checked lol. The n112 has a hose that goes into the passenger fender.

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[rollerton]

Maybe it's the wording- it's not the 'bottom' of the airbox. It's actually the very front of the airbox, but on the bottom half. Right behind the passenger headlight. There's a pipe that comes out, goes 90* almost straight down to the SAIP. But that's the intake for the pump and has nothing to do with your problem.

[TT Wagon]

Im going to check all vac lines and routing. Found a diagram for my set up( sai pump at back if engine ) and believe ive been looking at the evap (n80?) Valve like a dumb ass. So now that the kid is at school ill ne tearing into this thing.

On a side note, the esp and abs light issue i have AFTER forgetting to plug maf back in i believe is intermittent. Went to car was yesterday, and no abs/esp lights. This morning in the other hand they were on. I remember reading a thread about this issue so lets hope i can find it.

And two, pretty sure my driver side heat shield is loose, would it hurt anything if i took the heat shields off? The rattling is annoying. Lol

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