Just bought a 2000 A6 4.2 Quattro with 115k miles. Lots of questions.
First the CEL light came on after 1 hour of ownership. Pulled code with a reader and it says 0422 low catylist. I assume that means one or more cats need replaced or the o2 sensors. I will talk with the used car salesman tomorrow about that but you never know what to expect from them. If I have to take care of this myself, anyone have suggestions on low cost way to fix? Cheap cats to cut in? I saw a new cat online for about a $100 that would have to be welded in. Anyone have experience with these? The other alternative is more of a oem looking unit for about $400.

Next, I assume with this many miles the timing belt needs to be replaced? Is this a job for the middle of the road backyard mechanic? I changed the timing belt on a ford 4 cylinder with variable valve timing and it was a nightmare. Does anyone have step by step instructions? recommendations?

The car did not have an owners manual. So much electronic stuff I don't know where to start on which switches do what. Any free resources available to get the basics?

Love the car and look forward to several years of fun on the road but not so much in the shop.

 

The OBDII code you pulled is a bit more specific. It means that the, "Main Catalyst for Bank 1 is Below Threshold", more than likely faulty. Your car has four (4) catalytic converters. Two on either side of the exhaust sytem for each bank or cyclinder head. Bank 1 is the passenger side of the engine, and the Main Cat will be the one closest to the engine. I have always felt that replacement units from an OEM supplier are best and will usually fit and perform more properly, but will tend to be a bit more expensive. You can shop around and find and OEM replacement from a supplier other than the dealer...so its possible to find one at a lower price that doesn't have the usual dealer mark-up.

Your question concerning the TB is a good one. Unless you have documentation showing the TB service has already been completed, it wou be a god idea to have that done ASAP since there is no way of confirming the work. Its an expensive job, but much, much cheaper than repairs if your belt or some related component fails. If you're mechanicaly inclined, you can do the job yourself with the proper tools and a good service manual or reference CD. There is a very good DIY post on this job posted in the, "Tech" section of, "Audi World". There are also DVD's that can be purchased online that document the procedure step by step. JHM Motorsports has a great DVD you can buy online...these two above, along with my Bentley manual are what I will be using as a reference when time for my TB job comes.

As far as the owners manual, I feel that every car owner should have one specific for their vehicle. Shop around for a used one online, or just break down and spend the money on a new one. There's nothing better than knowing how to use the features your car is equipped with and having a basic reference guide for its care and maintenance.

Hope this helped. Good luck with the car and welcome to the Audi Family. Remember, if you take care of it...it will usually take care of you!

 

CEL one hour after ownership. I suspect they used trouble code reader to scan & clear the code before you test drive the car and before you take over the car... they can also disconnect the battery terminals to get the ecu in sleeping mode for 65 miles or so.


Check this out... www.bigdaddiesgarage.com

 

It sounds like the car dealer passed the buck on you. They just didn't want to fix it themselves... Gosh, don't you just love these sheisters?
Do they have anything like a "30-day money back guarantee", or did you buy it "as is"?
In the latter case you're stuck with it.
Obviously they didn't disclose to you such an important underlying problem.

 

Thanks for the input.
So far the dealer appears to be willing to at least look at it. They can not get it in for a couple days but they sound positive regarding taking care of the cat problem. But they have not officially agreed to pay for anything yet. I will let you know how it turns out.

I have done a couple timing belts on other vehicles. One of the jobs was nerve racking because it was variable valve timing. This may be the same. On the other car I was nervous to start the car after doing the job because the process left me wondering if it was set properly. All went well but it was a non interference engine. This one is not so the risk is a little higher.

Again thanks and I will let you know how the cat issue turns out.

 

Use the cam bar tool and cam timing won't be an issue.

 

Well, on the CEL issue the used car dealer took care of the problem. The previous owner had rodded out the front cats. The dealer paid to have new cats installed and now no CEL. However the engine does not sound as aggressive, I liked the v8 sound before.

Now I need some keys with programming, prepare for a timing belt replacement, and a free owners manual or pdf.