No disrespect, but this is absolutely wrong. My pump is bad and the fuse is blown. The CEL illuminates after 2-3 cold ignitions. And since this pump is only for emissions purposes i left the fuse blown and i clear the code every 3 weeks or so. and it comes back after the 2nd or 3rd cold start.

 

Would SAI cause it hesitate and stutter in 1st and 2nd gear. In a 2003 A6 3.0? Or is that a whole different issue.

 

No. The pump is only On for one minute on cold starts.
Check your car for codes.

 

I am having a problem with my 2001 Audi A6 Quattro 2.7T, it has over 200k miles and i bought it 6 months ago.. about 2 months ago it started making a really loud sound with the cold start which after reading this forum im guessing its a SAI pump 3 days ago the check engine light came on and it was P1411 and p1423 which is secondary air injection system bank 1 and 2 insufficent flow. We cleared it and it didnt come back on until this morning when i started my car it didnt make the loud noise at all which only lasts about 20 seconds tops when it did make the sound and there is the word FUSE above my mileage. I have looked all over the internet for the FUSE that deals with this problem and ive seen 40 which in my car says HORN has nothing to deal with the pump. I need to know what to do. Replace the pump? How do i find this fuse? and what will it say on the panel? Please someone help me out before i go spend tons of money tryna get this fixed! Anyone with the exact same problem on the exact same car? THANK YOU!

 

The reason your SAI Pump went out was because of water vapor damage. Water vapor gets into the pump because your Kombi valve(s) got full of carbon build up & crap that keep them stuck open.

The Kombi valve is like a one way vacuum check valve to let air through the SAI Air Pump into the engine on a cold start to heat the cats. Air should be able to be pumped in but not let out.

Therefore, when combustion occurs it does produce water vapor that is forced out of the Kombi valve and into your SAI Pump which degraded the bearings & killed the pump (via the dentist drill noise)

Change both Kombi's, SAI Air Pump & the hose that connects them together (can be fabricated to save $$$)

With these codes you can't pass emissions but it wont affect performance too much. Causes a slight nearly unnoticeable stutter at idle, allows unwanted hydrocarbons to enter the air during a cold start up & could ruin a cat in long term situations. All very minor.

I have a 2000 2.7T, I fixed this on my car & have done the job at least 10 times before. I sent my pump to Cardone for some R & R rather than spend $400 for a new one. Another option that I am going to do myself at some point is to remove the damn SAI system, gut my cats (adds HP), move the O2's to trick the ECU & flash the SAI system from my ECU. Its only used at cold starts to reduce emissions that are higher when the cats aren't heated up to op temp, so F*** it!

 

Thank you everyone for the replies! Hxgaser is the winner on this one as it ended up being the very small Vacuum hose connected to the T-connector (part 16) in this diagram 2001 AUDI A6 QUATTRO Parts - AudiUSAParts.com.

This hose was quite difficult to access and because of its small size, it was a pain to get the old one off and the new one on. I delayed posting a reply as I wanted to ensure that the problem didn't resurface and in Minnesota we had about 90 degree weather consistently up until recently so the pump wasn't kicking in. However, I have been driving it now for a couple of months (2 weeks with cold weather) and the CEL hasn't illuminated. One thing I did find interesting is I don't hear the hair dryer noise anymore when I start the car. I wonder if this is because that noise was caused by the leak in the Vacuum line.

In any event, thank you all for the posts, I believe this issue is put to bed and hopefully I can enjoy my Audi again for sometime before the next adventure :-).

Thanks again

 

I hate those (and the corrugated PCV hoses that always break, and the "Y-pump" piece that fails and pressurizes the crank, etc.)

Have you removed the 'damn SAI system' yet?
Any good DIY you can point to?

All my cars have cats removed, rear O2 tuned out, stage 1 or stage 2 tunes.

 

Been reading about your problems with your SAI system. I have the same codes on my 2003 A6 + code 17862- short to ground on oxy temp sensor 1. Curious to know if you ever found the fix for your CEL. What was the problem? C/bob