Blocked Catalytic Converter

For the last 3 or so weeks (how long it takes to get in to see the dealer) I have been driving around in a very sick GTI.

I thought it had some kind of boost leak even though I had visually inspected the diverter valve and it looked fine. The car basically felt like driving a 1.6, worse than a naturally aspirated 2.0, no boost what-so-ever. It also had a crap sounding exhaust note (like a Hyundai Excel with a sports muffler).

I got it back from the dealers today, and there was no problem with the turbo system (they pressure tested it). It turns out that the catalytic converter was blocked. So they've replaced the entire downpipe including both catalytic converters. Now it runs better than ever! It's a pity they couldn't have replaced it with a 2.75" mandrel bent downpipe with 200cel metal cat!

What would cause the cat to be blocked in a car that is 7500km old? A factory reject? Unless it was physically damaged when I had flywheel repairs done by another dealer? Anyone ever heard of this happening before?

For the record VAGCOM showed it as charge pressure minimum threshhold exceeded (can't remember the DTC) and P0420 O2 efficiency below expected range.

holy crap! didn't they tell you why the problem occurred?
you must feel relieved that the problem's fixed.

First time I've heard of that happening! :eyebulge:
Did they not give you any explanation about what was wrong with the dp/cat?

Nice to have the car back to top form again, I bet.

Their explanation was that they never heard of it happening on such a new car either.

Yes, I'm glad it wasn't a stuffed turbo or something.

Unless they dropped it when they did your other repairs there isn't a lot that should cause it to block within that time frame... running leaded petrol or avgas might do it.. and stuff your O2 sensors at the same time. Otherwise direct force to it causing the innards to crack and collapse would be my guess.

after hearing your symptoms that was the last thing i was expecting!
still good to hear you have gotten it all fixed and your not running like a lancer.
you recon its time for another drive in the hills now?? :happyanim:

DRMAT said:

Unless they dropped it when they did your other repairs there isn't a lot that should cause it to block within that time frame... running leaded petrol or avgas might do it.. and stuff your O2 sensors at the same time. Otherwise direct force to it causing the innards to crack and collapse would be my guess.

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Those were my exact thoughts. The monkeys that attempted to fix the flywheel imbalance or whatever it turns out to be, most likely bashed, dropped, or crushed the exhaust whilst trying to get at the flywheel.

zz2 said:

after hearing your symptoms that was the last thing i was expecting!
still good to hear you have gotten it all fixed and your not running like a lancer.
you recon its time for another drive in the hills now?? :happyanim:

Click to expand...

Could do, but you'd have an unfair advantage. They decided to reflash my ECU, which means I have to wait until the new year for Superchips to come back off holidays before I can load the Bluefin back in. Although, since I've been driving it in the sad state it was, it now feels like it's been chipped anyway!