I have a 1998 Audi A6 that just failed the IL emissions inspection test. The trouble code is PO411 - Secondary Air Injection System Incorrect Mow Detected. The check engine light is on, but seems to stay on constantly despite repeated trips to dealer.
Can someone educate me about this problem before I go to dealership to get fixed so I know what to expect. Any estimate on repair cost would be appreciated.
Code P0411 is air injection flow there are many possible causes the most common is the vacuum hose for the injection (combi valve) brakes off. The air injection pumps are also know to fail but not as often the combi valve can fail as well but not as often
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SAIS Pump - Pumps fresh air into the exhaust manifold.
SAIS Combi-Valve - Controls flow of fresh air into the exhaust manifold when vacuum is applied.
SAIS Solenoid - Controls the vacuum to the kombi valve, vacuum is sourced from the intake manifold.
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(SAIS) = Secondary Air Injection System
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The purpose behind the whole thing is to get extra oxygen into the exhaust stream to help heat the catylitic converter faster... that's it. The OBD expects to see a 'lean' condition from one of the O2 sensors when the pump runs... if it doesn't it trips the code.
This will be a small belt driven air pump for emission control, that directs air either to the intake or through the exhaust. When this codes, the problem will be either that the pump has failed or one of the in line check valves has failed. The check valves are located on the hoses that lead to and from the pump.
Although my listed expertise is computers, I have many years as a automotive shop foreman. I developed arthritis and had to do something else, computers don't work my hands as hard. If you don't believe me. Call the service dept at your local dealership and ask what the secondary air injection system is, they will tell you at no charge. dustboner's solution sounds just like mine and he a car guru.
Test the check valves by taking them off and blowing through them. Air should only flow in one direction, if it flows in both, then there's your problem. Test them all, don't assume that the first bad one you find is the only one. If this fixes your problem, I would appreciate the fixya rating, even though I'm just a computer expert.
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Hi ecudave, i will go for a tune-up / clean up; the injection system, intake and replacing the sparks, regular maintenance like this will surely clean you emmision. as per re[air cost or shop costs, that will still depend on which part to clean or to work on or even to replace like the spark, but it will not be more than $400.
hope that helps
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I would feel more comfortable if someone that specialize in autos, not cameras and computers, attempt to answer my inquiry. The vehicle has been recently tuned up.
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