SAI CEL Codes

B6 A4
#1

So, I went to Pepboys today to pick up some hose clamps, and I had them scan my car for codes to see what came up (besides what I knew was there). I had P0491 and P0492 for the secondary air injection system, insufficient flow on bank 1 and bank 2.

The past week or two, I have noticed that when my car is cold, I get a noise coming from the engine bay that sounds like a high speed fan going bad, like a whirring noise I guess would be a way to describe it. It only happens when the car is cold, and only for the first minute or so. Reading about how the SAI system works, it makes me think the codes are related to the noise.

I tried to narrow down the sound today, but can’t pinpoint where it is coming from. The best I could tell, it sounded like it was from the passenger side somewhere. Could the noise be related to the codes for the SAI system? Also, would anyone be able to help me fix the SAI system, no matter how useless it is?

#2

I have the same problem as well and all I know its its not needed and you can pull the thing out cap it off and get the JHM tune to delete the code. So in my mind 3-500 to fix SAI system when I can instead buy a JHM tune and upgrade while fixing the problem. Sounds like a fair deal to me.

If you really want to fix it I would check the hose because I think I read that most of the time its the hose that fails and not the pump. But i’m not good with technical things so don’t take my word for it. I’m sure someone else with more experience will chime in to help.

#3

Thanks for the info. I figured it is probably a bad hose somewhere. I just wish I could find a better picture somewhere as the pictures I found in the Bentley manual weren’t all that helpful :-\

#4

Here ya go…

http://forums.audiworld.com/showthread.php?p=15391524

#5

So, I finally got around to looking at this, and I found the issue. The exhaust hose on the pump outlet came off. As far as I can tell, the hose is still good. Question is, how do you re-attach the hose? It has some odd connector on the end. I only really have access from the top of the car right now, and I can get the hose onto the outlet, but regardless of how hard I would push on it, it wouldn’t snap back onto the connection. Anyone that has removed the hoses before care to provide some help on getting it reattached. I’d like to get rid of the codes and the hair dryer sound my car is making. TIA

#6

I think the hose clips the same way on for both ends… I’m taking mine out tomorrow so I’ll let you know. Lol you could always unplug the pump to avoid the sound :stuck_out_tongue:

If you remove the SAI pump, but don’t remove the piping for it, where would you cap it off? I have limited time to take the pump out and ripping those pipes out isn’t going to happen anytime soon.

#7

I got some more info at Audizine last week, and since I have some time tomorrow, I’m going to try and get it re-attached. It has to go on a specific way, apparently I wasn’t turning it far enough to get it to slide on. Hopefully I can get it as the hair dryer sound is really annoying.

#8

The first time I tried to fix this, I spent probably 10 minutes trying to get the stupid hose back on. Went out today to fix it, spent 5 minutes total (taking everything out, putting hose on, putting stuff back on, and turning the car on to see if it was fixed). Feel like an idiot that I didn’t get it the first time, but I guess I wasn’t quite turning the hose far enough to get it to snap in place the last time I tried. Hopefully it stays put though. That’s 2 codes down (I hope) and only one left for my CEL.

#9

Well, the hose came off after driving around for a day, and the CEL codes came back with it. So, I had some free time on Saturday, so I went back out to try and put it back on again. In my 20 minutes of trying to get the stupid hose back on, I found out that the last time I tried and thought I had it, only one side of the connector snapped into place, and the other side was never fully on. After screwing around with it for 10 minute, I got some grease and put it around the opening on the SAI motor/pump so it would slide into place easier. After another 5 min or so of trying to get the hose on, I eventually got both sides to snap into place.

Given how much effort it took to get the hose on, and also how much effort it took to get a the SAI feed hose off of the airbox, I’m really wondering how it ever came off in the first place. I doubt many people will have the same issue, but if you go to do anything with the SAI pump and the hoses connected to it, I would definitely recommend working on it from under the car, as there isn’t really any room to do much from above like I was doing putting the hose on.

However, I did have a nice side-effect so far of getting the hose back on properly. I cleared the codes before doing a lot of driving this weekend (~200-250 mi), and I had a code for SAI flow low and catalyst efficiency for both banks. So far, all 4 codes have stayed away, and this is probably the longest I’ve driven without a CEL for probably a year and a half. Hopefully it stays that way.