ok so i was just happening to drive past my autozone when this happened. and i pulled in cause my CEL just came on, i ran the code its a P0411 the description is this, "The PCM has determined that the flow detected in the secondary air injection system is incorrect for the current engine operating conditions" ok so what the hell do i look for? what can i do ? im perinoid. this is the first CEL ive had.. the cars got 180k miles its a 99 a6 any help would be greatly appreciated.

 

P0411 error is for the secondary air flow, which is connected to the air box, but separate from the main intake.

 

Ok. So what does that mean.? What should I do? I dunno much about these things yet.

 

Hi. The secondary air injection system is used on emissions controlled cars to maintain the proper air/fuel mixture until the engine reaches normal operating temperature. It basically injects atmospeheric air into the cars intake system on cold starts to ensure the engine does not run to lean (starving for fuel) until normal operating temperatures are reached and the O2 sensors have warmed. In your case, I'm not sure if you were driving the car prior to the engine fully warming to normal temperature or not. If so, the load on the engine before it warmed could have caused the code, or it could simply be a vaccum or other air leak in the system caused by a torn/leaking hose or it may simply be a bad O2 sensor in your car. I would first have the code cleared first and warm the engine prior to driving it in the future. If the code reappears I would start with the most likely and cheapest issue first, by checking for an air leak, and then progress from there until the issue is corrected.
As for me, I usually allow my car to idle for at least a few minutes after each cold start. If you listen carefully, you will notice on Audi's that you can clearly hear the air injection pump running for the first minute or two after a cold start (kinda sounds like an exhaust leak).
I've included a link which may also be helpful to you and is informative on how the secondary air injection system works. Good Luck

http://www.12v.org/engine/index.php?section=hw&sm=2nd

 

^^^ what he said lol

 

What engine do you have?

 

i have a 2.8Q but i got the CEL cleared and it has not gone on since.. idk if its going to happen again or what..

 

Probably a vacuum leak of somesort. The following is a link to a 2.8L vacuum diagram. You may have a sticker on underside of your hood as well.

https://www.audiforums.com/forum/alb...&pictureid=575

Anyways, I had a leak from a rubber hose connected to the bank 2 one way check valve behind the head. Also the plastic line running to the vacuum reservoir gets brittle and tend to break. You can buy 5 feet of vacuum line from any auto parts store for a couple of dollars and replace pretty much the whole system. Hope this helps.

 

is the one your talkin about replacing a thin rubber hose that is on the top ? is it easy to replace?

 

Well there are mayn rubber hoses, but yes pretty much. It really is easy as pull the hose off, and slide on a new one on. But I would just wait until the code to come back. If the problem is not resolved, then it would take a couple of days for the code to come back.