I'm very new to working on Audi's... I bought a 2003 1.8T Quattro 5spd a couple months ago. I'm now in need of a new catalytic converter...

I've searched and come up with nothing so far... is it possible to replace a converter on your own? If so, how hard is it?Or is it best to just have a muffler shop or dealership do the work? I've heard this can get expensive... so if I can do it myself I'd rather do it instead of taking it somewhere...

If I have to take it to a shop to have the work done, I want to have a full custom exhaust done. If I go this route, does anyone know the part numbers of the mufflers from Magnaflow or Borla that best fit the stock location?

Sorry if this is a dumb question... like I said, I'm new to Audi... but not to working on cars...

Thanks for any help...

 

A 1.8T cat isn't too hard a job to tackle on your own, it may take some time though.
First up, buy yourself a can of PB blaster and let those bolts soak over night.
The top three bolts you can easilly get to by removing the air box, the bottom bolts you have to get from underneath the car, the bottom bolts have welded on flanges on most models so you won't need to counter hold it with a wrench.
Then just change it out.

 

Already have the PB Blaster... many uses when building my prostreet 72 Chevelle!!!

Just a couple more questions...

- Do I need to remove the exhaust system completely or just move it aside to be able to get the cat out from underneath? Or once all the bolts are out can I pull the cat out from above?

- Should I replace the O2 sensors when I replace the cat, or is that not necessary?

- I know aftermarket cats are sold everywhere, but if I just want a bolt in replacement do I have to buy through an Audi dealer or is there a website anyone knows of to get them through?


Thanks again for all the help!!!

 

You shouldn't even need to remove the exhaust system, it makes it easier though.

I would only replace the O2 sensors if your close to 100k miles.

To get the bolt in cat, you will have to get it from the audi dealer. Universal cats are weld in, and really doesn't belong on an audi IMO.

 

I'm a little over 100k miles... I haven't checked the service records from before I owned ityetto see if the O2 sensors were recently replaced (luckily I have all recordsbecause I bought itfromthe Audi dealership that it's been serviced at since new). I guess that'll tell me whether I should replace them while I'm in there or not.

Any idea on what a new cat will run? Just curious what to expect when I go to purchase...

Thanks again...

 

Here is the high-flow cat i just installed on my car a few weeks ago, $299. http://techtonicstuning.com/showpart...rtnum=253.167T
The Miltek high-flow cat is $899.

The cat on the A4 is between the turbo and downpipe, not between the downpipe and exhaust. Which makes it's location half in the engine bay half though the firewall. I have my turbo out right now so i'm not sure if you can remove it without removing the turbo first, i couldn't imaging how it would be possible since it's so tight in there. the 03 1.8 does not have sunk bolts on the cat/downpipe connection so you will need a friend to hold a socket or box wrench on it while you get the nuts from the under the car with about 2" of extensions on a ratchet.

I soaked those bolts for about 4 days and they still woudn't move so i ended up sawing the downpipe in half from under the car and puling the whole think up though the engine bay all still connected since i was replacing everything anyway and didn't need to save the old downpipe.

This is a great site: http://www.audidiy.com/b6a4.html
A good place to start would be here (Removing the turbo), from there it's pretty easy to see what you need to do: http://audizine.com/forum/showthread.php?t=52940

 

I can see the bolts on the top end of the cat, and like auditech79 said if I remove the airbox I should be able to get all of them... And I was under the car the other day while it was on a lift at a friend's shop and could see all the bolts that connect it to the downpipe... If I disconnect all the bolts and move the exhaust out of the way why couldn't I drop the cat out the bottom instead of removing the turbo to lift it out the top??? Maybe I'm missing something... but I'd rather not remove the turbo if I don't have to...

 

If your car has less than 80K miles, take it to the dealer. There's a federal 80K mile cat warranty. Not dealer warranty, federal warranty. If your cat goes bad before 80K miles, by law the dealer has to replace it. Pass this info on to everyone you know.

I'm getting ready to order one to replace mine, too, and have found several companies online that make direct fit cats. Magnaflow, Bosal, Milltek, etc. I haven't decided what to get yet.

There are CHEAP (as in inexpensive) ones to be found as well, but I kinda believe in the "you get what you pay for" philosophy.

Google search "Audi catalytic converter", "Audi performance catalytic converter" or "Audi high flow catalytic converter"

 

Did you notice the thread is over year and half old???

 

I found it helpful. at 140,000 miles the CEL is on and needs to get smogged. Now days aftermarket bolt in cats are available unless you live in Ca. I just had to shell out $1160 for one at the dealer. Meanwhile every body else can get away with as little as $300 for a 49 state version. Car is kicking out code P0420 every 60 miles after a reset. Also have to re-install stock air box and hose assy. Thank you C.A.R.B.