I purchased a 1998 A6 Quattro a little over 3 months ago. I bought the car for $8,000 from a Ford dealership here in town. When I got the car it had 126,000 miles on it.

Currently it has 131,000 on it. After driving the car for a while, a CEL came on. One of my roommates is a mechanic and when we did an oil change we ran the ODBII on the car. It came back with 3 codes. Specifically talking about secondary air flow. He said that there is a valve that puts air into the exhaust when the car is started and that it is probably sticking. After reading on the secondary air flow system, most people have said that it is actually a vacuum hose that has disintegrated.

My plans are to soon replace the fuel filter, air filter, new spark plugs, and brake pads all around. Although, I am not sure what to do about the CEL. Aside from the maintenance I just mentioned, what are some things I should do to ensure I get the most longevity out of the vehicle?

Also any suggestions on the CEL and secondary air flow?

This is my first european car and I believe I have a new addiction. Thanks for taking the time to read. Any input is appreciated

 

Check the vacuum lines...

 

https://www.audiforums.com/forum/sho...d.php?t=108874

Check this link!

 

Does your car sound like a vacuum cleaner when you have the AC on? if so your secondary air injection pump is bad. Part is expensive but many people just pull them out because it's not really needed on our cars.

Another item you might consider replacing are your pre-cat O2 sensors.

 

I don't know about this... Usually the noise that you hear when the AC is on is the secondary cooling fan. And it is normal. Also if you take out the secondary air injection pump out, you will get a permanent CEL.

As for the pre cat O2 sensor, no need to worry about it if there is no trouble code related to the sensor. But I do agree that some O2 sensor related codes may pop up if you have a vacuum leak.

 

Replace all the vac lines (especially the line to the secondary air pump below the air intake box) and check/replace the crank breather hose(s) ~ this took care of my CEL... you may have to clear the CEL a few times (but after clearing it for the 3rd time in 2 days mine stayed off)

While you're in there, (kind of unrelated) check/replace the coolant temp sensor (maintenance to get out of the way, becuase it will likely fail soon if it hasn't already @ your mileage)

... just some suggestions based on my experience that may help

 

Wow. Thank you all for the quick responses!

Where can I get new vacuum lines?

What are good spark plugs to use?

Also, I have found some headlights on ebay (mine are covered in salt deposit, thick yellow film that wont buff out) and asked the seller if they are xenon lamps (what i would like to upgrade to), he has told me yes. My question is did they make xenon lamps for 1998 a6q? thats what the lamps are coming off of. heres a link:

http://cgi.ebay.com/ebaymotors/ws/eB...m=270273716304

 

There is a product that Walmart/Advance both sell. I can't think of the name of it off the top of my head (clear eyes maybe?) but it comes in a silver bag with a pic of a white ford van on it. I recently used this to refinish my headlights (they were VERY yellowed) and I was extremely pleased with the results. They came out 10x better than I expected...$20 and a couple hours worth of my time...

 

You can also use PlastX which you can get at Walmart or Autozone. Excellent stuff.

 

You are right that the secondary cooling fan runs when AC is on and it makes more noise but what I'm talking about is unmistakeable. It's freaking loud! and you'll get a CEL when it fails...plus you'll know because of the vacuum cleaner sound it makes.

You can take it out. There's a writeup somewhere on these forums and it requires modification of a relay so teh CEL doesn't come on.