bennywhere

Hi there!

First of all, thanks a lot for this great site and all the feedback from expert users!

Now to my problem:
Over the last few weeks I've been trying to figure out the reason for the CEL occuring every 40 miles or so.

I get the following error using generic OBD-II and my laptop using Ross's VAG-COM:
17695 - Secondary Air Injection System: Incorrect Flow Detected P0411 - 35-00

It seems to be happen somewhat randomly: After a cold start, I don't see the CEL for at least 20 miles. But that's about as far as consistency goes. It happens when idling on a stop sign, or while driving on a highway with +60mph. Which gear I'm in doesn't seem to matter. The farthest I've gotten without a CEL going on is about 120 miles. Just to make the history as complete as possible, it's been rather cold around here (~0-30 degrees F).

My car is a 1998 A4 Avant Quattro, with a V6 2.8 liter engine, manual 5-speed transmission.

Based on some suggestions on this forum, I checked the vacuum lines, but there seems to be no leak. My mechanic suggested that it may be the air pump, but said that I should check with you guys before he spends hours troubleshooting, or worse, replacing the pump to find out it wasn't the pump. I do want to add that I have been very happy with my mechanic, and I think he definitely knows what he's talking about. However, I've put more money into this car over the past few years than what I want to, so I'd like to troubleshoot a bit on my own... with you guys' help!

If there's any additional info that you need, please let me know and I will post asap. Please be aware, though, that I'm quite a newbie on car engines.

Any help is greatly appreciated!

Thanks,
Ben

Pete@ECSTuning

SAI pumps are pretty common faults on these cars. The problem you are getting is spot on with a bad SAI pump. The pump runs during cold start conditions to help reduce emissions. A replacement pump runs about 200 dollars and up. We carry them, and likely for less cost than you will find awywhere else. Click here to order a replacement pump. You could order from us and we could even ship it direct to your mechanic if you'd like. Just add the item to cart and enter shipping information.

bennywhere

Just checked the SAI pump: cold start and the pump is running.
I probably should have searched the forum first... there seem to be quite a few posts.

However, if, based on the new info you guys can give me pointers, that would be great.

-SAI pump seems to be working.
-My mechanic tested the vac lines, which seem to be fine.

is it the combination valve??

Thanks!

davy1063

It could be the Combi Valve, Carbon gets in there and can block the valve open. I had the exact error code with my 2000 A4 1.8T. I replaced it and the code came back. I went as far as replacing both O2 sensors. It turned out it was a partially blocked Catalytic Converter. Do you have access to a VAG-COM? Run the readyness test.

Coca-Cola

I had the same issue on my '00 1.8TQM. It was a stuck combi valve. It was heavily carboned on both sides of the valve. One side is air from the pump while the other side goes to the head. The valve was removed cleaned and reinstalled. So far so good. I live in CT so the valve gets a work out this time of year and I did not want to replace the pump or combi valve without giving the cleaning a try. If you have fat fingers that was the only issue I could see in removing it but I also have a 1.8T. Good luck.

kustom

Hey I'm brand new to the forum, I purchased my 99 quatro with the 2.8 v6 from a friend of mine and after about 1000 miles I got the CEL with the same code alot of people are talking about. I'm currently going through the different things listed here to check but I'm wondering if someone can tell me what problems can be caused by this or associated with it?

Thanks a ton.

pgoyer

1997 A6 with 125k
Check Engine code P0411 weak flow of secondary air in Bank 2
Checked all vacuum and no problems
Air flow thru Combi valve no.2 OK
Air flow thru exhaust manifold was poor

Replaced Catalytic Converter
Problem solved for 3 weeks
Now it's back and the exact same symptoms, ie... poor flow thru bank 2 exhaust...
Is my engine killing my bank 2 cat?

Engine does not use oil, and I never over fill

I'm stumped....

jking

i also have some issues with my combination valve on my audi a4. there was a loud sound coming from the rear of the engine during startup. what would cause the combi valve to gave a loud ticking noise? anyone?
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audi a4 parts | -jimmy king-