Best Deal on a Cat 2000 Jetta

[Toby]

Who has the best deal on a cat for a 2000 Jetta? Failing anybody with a good price on one, does anybody have a used one they would sell?

[bbob203]

magnaflow high flow diesel cats are 80bucks.

[vanbcguy]

The Magnaflow ones are fine. I ran one for the last 4 years. Can't beat the price!

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[Toby]

How would you tell if these replacements are actually OK? What happens if you just bang the catalyst out of the housing? Do they smoke visibly w/o a cat?

FWIW I decided to try to clean this one. I back flushed it with the steam cleaner. I got a whole bunch of crap out of the cat. It runs fine now. Was dead slow before.

This one had a perfectly good cat until the brief run away. They engine gradually quit as I was sitting there with my foot on the brakes trying to figure out what to do next. I suspect that the cat plugging up is what killer the motor after 30 seconds or so. 

[vanbcguy]

The Mk4 and earlier diesels that have cats don't have any sort of downstream monitoring of the catalytic converter if that's what you mean.  The engine management system on a Mk4 or earlier TDI won't care if the cat is a hollow tube / doesn't exist / is otherwise modified.

Smoke isn't much different with/without a cat.  There is a noticeable difference in the smell of the exhaust though - my Magnaflow cat is most definitely doing something.

If you have managed to clean out the cat a bit and things are running better you are probably going to be able to save the one you have now.  The best way to clean it out is to get some serious heat in to it - give it a good long drive ideally with conditions that cause higher EGTs.  The cat needs to get good and hot to burn out all the oil that has collected in it from your runaway.

Seems like the ALH engines are a lot more prone to runaways than the earlier ones - was yours caused by a turbo failure?

[theman53]

The ALH engine has that flap on the intake that IIRC is called an anti shudder valve. It is supposed to stop a runaway if needed.

[Toby]

I got a huge amount of goo out of the cat with the steam cleaner. I ran it until the water was clear going into the bucket. Back and forward flushed it. That took me from barely able to move to drivable. After a 75 mile jaunt it is getting much better. Sometime next week I may take it for a high speed run up Snoqualmie Pass. That is always a good way to bring up the EGTs. The problem with serious heat in cats is that can melt the catalyst bed and seal itself off.

The flapper valve will kill the engine on an ALH, but only if you close it with a finger. It does not close when the key is shut off. It takes vacuum and 12 volts to make it close. It would be great if it did.

I think the clogging cat saved me from having to resort to other methods to kill the motor.

It was a wasted turbo that caused the runaway. I checked run out with an educated finger when I had the motor apart. It was not excessive with the compressor pushed in, but it had .125" end play and half again that much run out pulled out. I did not find that out until it was installed on the bench.

It seems to be a pretty nice car. Its for my wife and is way better than the 2000 Jetta TDI that I drive. She suspects that I will try to beat her out of the good one. Something I would never do. She appreciates nice stuff and will take car of it. To me they are almost all just cars. Mine is my office and I drive too many miles and spend too many hours in it to be nearly as concerned about washing it or vacuuming it out.

A tip for all car guys: I snagged an old built in vacuum cleaner system off the CL for $25 that I hung on the wall between the garage doors. Just slap the "on" button and drag the 25' hose out to the car and even a lazy f%#@ like me will vacuum out a car. The idea that I have to hunt up a shop vac and drag it out to the car, find an extension cord and then put all that stuff away afterwards insures that I will never do it. No excuse now.