# secondary air injector - incorrect flow



## watercooled320 (Feb 9, 2010)

06 rabbit, 2.5L, 82k. I've searched the forums on here along with google and I can't seem to find a straight answer or one that I'm looking for, so this is why I'm sort of re-asking the question. At the end of december, I had a very minor accident, which left my front bumper scratched, and the headlight mount broken. Not really anything that I can't fix. Two days later, my check engine light came on, so I took it to autozone and I got the P0411 code (secondary air injector, incorrect flow). The guy was clueless as to what it could be and told me to take it to the dealership. I searched the net for answers but couldn't find many good ones. One question is how likely would it be for a vacuum line or lines to go bad in a 6-7ish year old car? And, could the jolt from the accident have made a line or the secondary air injector break, crack, or go bad? Is there a vacuum line that runs somewhere along the front passenger side of the engine bay below the headlight? Honestly, I know nothing about vacuum lines, and finding a diagram online of where they start and end has proved impossible. I don't have the loot to just start fixing and replacing everything that it could be, so any help on this is appreciated.


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## tay272 (Aug 22, 2007)

Id say check the 2 hoses that route into your intake boot near the front of the car. Dont really remember how its set up stock anymore since its been a long time since my car was stock. There should be 2 hoses tho right before the MAF sensor, check and make sure they are on tight and didnt get knocked loose. Just somewhere to start.


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## Streetliight (Sep 5, 2011)

Secondary air line is one of the two hoses that the guy above me mentioned. It will be the bigger of two hoses that are plugged into the intake right before it goes into the throttle body. Having it disconnected may or may not throw a code, I've heard both scenarios. Here is a pic of the two hoses. 

http://img.tapatalk.com/d/13/01/04/epa8y5e4.jpg


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## watercooled320 (Feb 9, 2010)

Streetliight and tay272: thanks for the advice. that was one of the first things I checked after the light came on. I guess the next step would be to remove the secondary air injector to see if it is indeed cracked or not. It's almost impossible to see from either the top or bottom. I don't want to let this problem go to much longer, so i'll probably be doing the work sometime in the next week. If either of you have any advice or anyone else has advice, it's more than welcome. thanks, and again, it's appreciated.


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## watercooled320 (Feb 9, 2010)

Side Note: I've heard that if it is a vacuum line cracked, you get a rough/uneven idle. and if it's the secondary air pump, it will not run properly and the car sounds different on a cold start. My car runs perfect. I'm wondering if maybe there isn't anything wrong at all? Or maybe whatever problem there was, fixed itself, or in the several times i got under the hood to make sure everything was connected properly, I tweaked something and fixed it sort of accidently. I guess my other question is, if the light comes on, does it automatically go out if the problem goes away, or does it have to be manually turned off even if the problem has been fixed or fixed itself?


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## tay272 (Aug 22, 2007)

pretty sure it should reset after driving 30-40 miles. if u go over that and the cel is still on then u still have a problem


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## Anony00GT (Mar 6, 2002)

For starters, you need a service manual. VCDS would be helpful as well, as you can run the SAI output test with it. Neither are cheap, but they may pay for themselves with this repair alone.

The system is very simple, all it does is pump air into the exhaust to aid in proper heating of the catalyst and O2 sensors. It runs on cold starts only.

On cold start, the air pump will turn on. It blows air to the combination valve, which prevents exhaust (and associated condensation) from backfeeding into the pump during normal engine operation. On the 2.5, this valve is operated electrically, there is no vacuum line. When the pump is commanded on, the valve is commanded open. The ECU then watches the O2 sensors for a lean switch as air is pumped through. If it doesn't see the switch, it stores 16795 (P0411) in memory. If it fails to see the switch a second consecutive time, it illuminates the CEL. After seeing several consecutive instances without a fault, it may turn the CEL off, however the code will remain stored in the ECU, flagged "intermittent". You may need VCDS to read it at this point though, generic OBDII may not be enough.

On a cold start (ECT within a few degrees of IAT), start the car. If the air pump doesn't run, check power/ground at the pump. Bear in mind, it'll only be commanded on for about 30-60 seconds, so if doing this manually you must move impossibly fast like greased lightning. This is why VCDS is handy, you can tell the ECU to command it on and check for power, you should also have good ground to the pump at all times. If you've got both power and ground and the pump doesn't run, replace the pump. If you're missing power, get out the wiring diagram and figure out why. If the pump runs, make sure all hoses are connected. If they are, remove the combination valve and test it out of the car. 12v and ground applied, it should be opened; no power, it should be sealed shut.

Good luck.


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## watercooled320 (Feb 9, 2010)

Taking the SAI out and checking it this weekend. Hopefully I can get this figured out so the CEL stops taunting me. Plus I have an emissions test coming up :banghead:. Thanks to everyone for the suggestions. Gonna try them before I rip it out and check it.


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## kalebskaggs (Apr 18, 2012)

Saving.

Sent from My MKV


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## vrsick147 (Jun 18, 2007)

if your pump is ok there is and updated hose and new style sensor kit you will have to installed to fix it correctly


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