For anyone thinking about removing the SAI (Secondary Air Injection) system

[hahnmgh63]

I do have some good news. With the Secondary Air Injection System removed it is much easier to remove both valve covers if you need to do the gaskets and it gives a little more room overall in the engine compartment for something that only really works on cold starts and only for about the first minute or more.
If your thinking about it here is the good news. Many of you know I just got my car back on the road after 6 months of work. I immediately got the CEL for the SAI system as I had expected, and planned to get it tuned out with a custom code from Viper or Eurocharged. Well I took the little N112 valve (small little solenoid valve with two vacuum ports that sits under the front section of the aircleaner where the removable panel is that you pull to add oil) and looped a vacuum line from one port to the other (just to keep it clean inside from contaminents) and re hooked the little valve back up on top of the intake manifold and cleared the codes and 100 miles later still no CEL. I still would like to get a Viper custom tune but the SAI codes I don't have to worry about anymore. Car is running great right now and I haven't even run it hard and it pulls like a freight train. I threw a tranny code the other night on the first real run in the car up for beer night, P0735 5th gear unavailable, and went into TCU limp mode. Pulled over and restarted and the code went away. Fine on the drive home and pulled into the shop & rechecked the tranny fluid level and it was a full quart low. Can't believe it must have still had some air in the system and/or cooler lines. Did 100 miles in it today and she ran great & shifted better than ever.

[ttboost]

I WAS thinking about this. Will no SAI fail you at emissions, if you have it? My SAI pump sh*t the bed a month ago and I have been driving around with the CEL on, becaue I am too lazy to reset it every time I go out. I sure miss that "747 landing in my driveway" sound every time I start it up though...

[QuattroRS]

So you're saying that there is no need to code out the CEL? Just keep the solenoid and loop the vac lines?

[4everRS]

Awesome work Mark! What a project. If you have time, could you post a pic of the vacuum line your referring to?

About the trans fluid, is there some easy way I don't know about to check the fluid level? When we did mine, I needed to add fluid later. It took 2 more quarts. I still think it may need more.

[MaxRS6]

Woo hoo- Congrats Mark and thanks for sharing your experience with us!

[hahnmgh63]

There is no easy way to check the fluid. I just start the car and drive it about a mile and pull it into the shop and onto my lift (drive on type) and lift it up about 4' in the air and also hook up the laptop to run the transmission module, after 1/2 to a 1 mile drive it is around 30'~35'C temp. Just pull the filler plug and if fluid isn't dripping you stick the filler pipe in (I have the stupid expensive Audi tool that has the little hook end on the filler pipe) and start adding fluid while watching the tranny temp on the laptop. I have the ZF manual in PDF format if anyone would like it E-mailed to them. They also have a blurb about filling the front & center (Torsen) differentials too. hahnmgh@yahoo.com
ttboost, I can't say for sure you will pass emmission without out it but it shouldn't be a factor as your car is warmed up when you get to the emmissions station, for the same reason RS6's pass emmissions with the pre-cats gutted, the main cats are warmed up by the time you get to the emmissions station to do the testing. I have no CEL but will run Vagcom on it today to make sure there are no other codes. I did have and intermittent Bank1 Sensor2 code which should be due to the Catless Millteks, I expected both rear O2's to be throwing codes and a CEL but thankfully no. I may even try to one of the 034 O2 sensor extension pipes until I can get a recode to remove the secondary O2's. If you are interested I do have my SAI air pump, that is if you really miss that sound. What is your SAI fault code? It isn't showing the N112 valve is it? Or is it showing J299 or V101?

[kday]

Trans procedure sounds just like the one for my automatic C4 A6... boy I wish they hadn't deleted the dipstick. I keep meaning to fabricate one, since my A6 has a slow trans fluid leak and I have to top it up twice a year. I don't have a lift so I have to climb under the car on jack stands while it's running. For whatever reason that car likes to be overfilled so I don't bother with the warm up.

[ttboost]

There is no easy way to check the fluid. I just start the car and drive it about a mile and pull it into the shop and onto my lift (drive on type) and lift it up about 4' in the air and also hook up the laptop to run the transmission module, after 1/2 to a 1 mile drive it is around 30'~35'C temp. Just pull the filler plug and if fluid isn't dripping you stick the filler pipe in (I have the stupid expensive Audi tool that has the little hook end on the filler pipe) and start adding fluid while watching the tranny temp on the laptop. I have the ZF manual in PDF format if anyone would like it E-mailed to them. They also have a blurb about filling the front & center (Torsen) differentials too. hahnmgh@yahoo.com
ttboost, I can't say for sure you will pass emmission without out it but it shouldn't be a factor as your car is warmed up when you get to the emmissions station, for the same reason RS6's pass emmissions with the pre-cats gutted, the main cats are warmed up by the time you get to the emmissions station to do the testing. I have no CEL but will run Vagcom on it today to make sure there are no other codes. I did have and intermittent Bank1 Sensor2 code which should be due to the Catless Millteks, I expected both rear O2's to be throwing codes and a CEL but thankfully no. I may even try to one of the 034 O2 sensor extension pipes until I can get a recode to remove the secondary O2's. If you are interested I do have my SAI air pump, that is if you really miss that sound. What is your SAI fault code? It isn't showing the N112 valve is it? Or is it showing J299 or V101?

I've had the same codes for the longest time. If I reset them, they WILL come back.

17979 - bad engine mount (I know about)
17831
17819

Wondering if the SAI is causing these or do I have bad O2's or is my airbox STILL leaking, or.....

[hahnmgh63]

I'm sure you've already been through these but:
17819/P1411/005137 - Secondary Air Injection System; Bank 2: Insufficient Flow

Possible Symptoms

Malfunction Indicator Light (MIL) active
Possible Causes

Fuse for Secondary Air Injection Pump blown
Vacuum Hose(s) leaky or collapsed
Piping between Secondary Air Injection Pump and Combi (Secondary Air Injection) Valve leaking
Secondary Air Injection Solenoid(s) faulty
Combi Valve(s) faulty
Possible Solutions

Check Fuse for Secondary Air Injection Pump
Check Vacuum Hose(s)
Check Piping between Secondary Air Injection Pump and Combi (Secondary Air Injection) Valve
Check Secondary Air Injection Solenoid(s)
Check Combi Valve(s)
17831/P1423/005155

From Ross-Tech Wiki

17831/P1423/005155 - Secondary Air Injection System; Bank 1: Insufficient Flow

Possible Symptoms

Malfunction Indicator Light (MIL) active
Possible Causes

Fuse for Secondary Air Injection Pump blown
Vacuum Hose(s) leaky or collapsed
Piping between Secondary Air Injection Pump and Combi (Secondary Air Injection) Valve leaking
Secondary Air Injection Solenoid(s) faulty
Combi Valve(s) faulty
Possible Solutions

Check Fuse for Secondary Air Injection Pump
Check Vacuum Hose(s)
Check Piping between Secondary Air Injection Pump and Combi (Secondary Air Injection) Valve
Check Secondary Air Injection Solenoid(s)
Check Combi Valve(s)
Special Notes

On vehicles with rivets holding the plastic body halves of the Secondary Air Pump together check to see if the rivets are falling out. If they have fallen out or are loose you may be able to bolt the pump back together if the motor has not failed.

[ttboost]

Can you take a quick pic of your SAI bypass mod?

[hahnmgh63]

I'll get you a pic tomorrow afternoon/evening as I was away all day today. I got the SAI block off plates from 034 Motorsports (same as the 2.7t SAI). Then just pulled the pump and the pipes & hoses and the vacuum line running under the intake manifold to the N112 valve at the front top (under removable carbon fiber cover) of the intake manifold.

[JSRS6]

Reported on all threads.

[Erik]

Reported on all threads.

Thanks...all spam should be gone now.

[hahnmgh63]

Here is a pick of the valve. As far as your two SAI codes, I would unplug the SAI pump if you haven't already and then see what comes up after resetting the codes? My pump is unplugged and removed and the plug is just tie wrapped to the engine harness.

[SteveKen]

Interesting. . . I've had my SAI removed and block off plates installed for about 7k miles and have only had the SAI CEL twice. I think it happens maybe only when it was cold out?

I swapped the Tee fitting that feeds the valve pictured above for a straight piece. I never thought to loop the vac hose like you have done. I wonder what that actually does? I didn't think there would be any feedback to the ECU if it was installed or not? Just as long as it's plugged in.

One thing I was thinking of doing was installing a resistor or some bypass circuit on the SAI pump plug, itself. Any thoughts on this?

I've learned that PA state inspection will pass a 2003 MY car with one readiness code failing, so this might not be as big an issue, personally, than I originally thought. However I do plan to sell the car eventually. therefore, coding it out in the ECU is something that I intend to have done.

[kday]

I guess the real question is what information the ECU uses to determine the SAI system is working. I don't know the answer but hopefully it's not as complex as the way that the catalyst efficiency is measured (i.e. by looking at both the pre- and post- cat O2 sensors and using a model of the catalyst to determine if the signals are plausible.)

[hahnmgh63]

I also thought about the resistor but figured that the solenoid valve installed would work fine and so far (250 miles on the car) I am no longer getting any SAI codes. ttboost is getting different SAI codes and I'm wondering if that is because he has a bad pump and still has it plugged in whereas my pump is completely removed with the plug just zip tied to the firewall engine harness. I probably need to put more miles on my car to see for sure, and I could check the resistance of the solenoid valve but I would want a OEM looking plug to hook the resistor inline with to make it look somewhat OEM, but then the small Solenoid vavle is just that, small, so maybe I'll just leave it as is. It is nice to get rid of the SAI pump though.

[ttboost]

We have strict emissions laws here and I would like to leave it in place, with some kind of bypass for now. Clearly the ECU is looking for the SAI pump to be running on startup, if it's not, boom, code. Has anyone here "coded out" the SAI pump? This would be the simplest for me, as I can renable it when and if I ever get a new pump?