Nichole77

I have a 2001 Audi A6 2.8 Quattro. Last week I got the P1411 and P1423 codes and my mechanic said he checked for leaks and couldn't find any but when he tested the air pump it didn't work. So I had that replaced last Thursday but when I was driving last night the check engine light went on again and I got the same codes. Now I'm wondering if he was being honest about the air pump. I really don't know too much about cars but I try to understand so I have an idea about what's going on and don't get screwed. I remember the last time I had those codes something was wrong with the catalytic converter. I was wondering what else should be checked/causing these codes. Thanks in advance!

Nichole

tester123

Hello Nichole,

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)


If you don't have experience working on cars I would say it is tough to determine by yourself if the tech is being honest with you (you could get a second opinion). It could be any of these: vacuum hose(s) leaking or faulty secondary pump / air hoses or faulty "combi" valves (possible carbon buildup) that open for the secondary air to go to exhaust or, solenoid (essentially an electronic valve) that supplies vacuum to these "combi" valves towards the back of the engine.

Since it is happening on both banks (hence two codes - google them), I would suspect these components:

Secondary air pump / hoses / fuse(s)
Solenoid to supply vacuum to the Combi valves and / or vacuum lines broken
Finally, the combi valves themselves.

When you start the car in morning or when engine is completely cold, do you notice:

1) Engine revs higher and after a minute or so drops down rpm to idle?
2) During this time, do you hear any noise towards front passenger side headlight (lower) - kind of like a hair blower turned on and off after a minute? This is noise is different from higher engine rpm or giving gas and engine "revving" higher...

Check those and if you can hear that blower sound, chances are pump is good and you can start looking at other issues mentioned above.

Post back and let us know.

Airbag

just wondering, can the combi valve be removed and cleaned ? looks like a bitch to get off

tester123

Of course, it can be removed and cleaned. Just search on this forum for it. But, before you go down that road, did you eliminate other possibilities? Did you check vacuum lines? Vacuum Solenoid? Fuses? Air pump itself? Hoses?

I'd start with simple stuff like vacuum lines. They are known to become brittle (towards the exhaust so, it gets nice and warm down there ya know!). Then work your way to ensure vacuum is holding.

If you are looking to fix this on your own, a VAG-COM tool is a must! If you are lucky and its just a vacuum line and you find it, great! Otherwise, to do any sort of diagnostics and troubleshooting, you need this tool. Google ROSSTECH.

jcman

Sounds like a bad Secondary Air Injection(AIR)soleniod valve N112
or possible stuck combi valves "both" based on those 2 codes.

tester123 is right on the mark with VAG-COM because the N112 valve can be simulated and confirmed along with the SIA pump running, sounds like someone was real sure to replace a part with out the basic diagnostic checks around the real problem.

Nichole77

Thanks for all of the information! Since the air pump was replaced last week, I guess I will just have to take his word about the old faulty pump (he said he tested it). It does make me think they just replaced the part without actually checking for the real problem - exactly why I wish I knew more about all of this! I took it back to the mechanic this afternoon...If they find it is something else or a bad combi valve, I'm wondering if I should question whether the air pump needed to be replaced. He did offer for me to take the old parts if I wanted them. Maybe I should have to confirm the old one was bad. I will post when I hear back from them but this will help me understand what's going on and now I know what questions to ask! Thanks again!

Airbag

"yes" would have worked too

tester123

Yes

jcman

Good luck with that and keep us posted with the results, just remember that only two 12 volt events occur "one to the solenoid valve and one to the sai pump" and on the vac side after the sol valve works it pulls the combi diaphragm to open and function when called, two essential checks are in order best by vag-com and a VOM meter.

Nichole77

Sorry, I forgot to give an update! So the tech spent 6 hours cleaning the valves and didn't charge me because he said they should have done that when replacing the air pump even though he has never seen that occur at the same time (he still insisted that they tested th air pump and it didn't work). Hope that did the trick although ever since I had work done on it I notice it shakes/sputters sometimes when sitting at a stoplight. Crossing my fingers that it gets me another couple of years before it dies. Thanks again for all of the help/advice!