The cartridges did not look bad while the computer reported a low catalyst efficiency error on two banks so four cartridges to be replaced. By the way, I will mention that the indicator of wear and tear of catalytic converters is not always their appearance, they may look very good and may no longer work as a result of natural wear of the precious metal elements contained in the catalytic converter cartridges as was the case here. 

The catalytic converters already came to us empty so I'm skipping the brooding about what and how and why because the causes of wear or damage to the catalytic converters could be many. We measured the cans of catalytic converters and flew for the cartridges we had on the shelf. The 130 mm diameter  80 mm high cartridges turned out to be ideal in terms of fit. Of course, they were also selected according to the relevant emission standard and capacity.

A car with a mileage of 342000 km, a lot and not a lot, certainly the catalytic converter could look better if not for gas. LPG due to its higher combustion temperature will always leave a mark. In this case, it was enough to drive the last 30,000 of the 342,000 km to destroy the catalytic converters. As you can see the cartridges very badly damaged, melted and cracked, typical with lpg. We put in new metal Euro 4 cartridges according to the specifications. The cartridges with a diameter of...

For the relatively low mileage, the catalytic converter is very damaged. At first I thought it was an oil defect, however, the culprit turned out to be a leak in the exhaust manifold, which on this model is liquid-cooled and connected to the head by water channels, in addition, it is integrated with the turbocharger as a whole. 

Another case where oil killed the catalytic converter ... Anything that does not burn in the cylinder will burn in the catalytic converter irreversibly destroying the ceramic cartridge. Whether it is oil entering the combustion chamber and then further into the exhaust or unburned gasoline, which will burn in the catalytic converter, the effect will be similar (I greet, by the way, admirers of pops and bangs or so-called popcorn ;-) )

Ours were here... ;-) The customer brought catalytic converters for regeneration, which he had already had for regeneration about 2-3 years ago.

The catalytic converter looked normal.... No oil defect, no ignition defect so catalytic converter whole, not melted, not clogged, zero mechanical damage and yet not working.

The catalytic converters came to us empty. The car from the USA so it was probably damaged, and often gets exhaust as a result of which the ceramic, which is located inside the catalytic converter housing, breaks and over time such a damaged cartridge is spat out by the exhaust. Due to the sporty nature of the car, the customer opted for 200 cpsi capacity sport cartridges. 

Unusual in the Polish reality, the customer decided to regenerate catalytic converters before the sale. It is known, paying half a banana for a car, a person would like to use it relatively trouble-free and enjoy, it is already safe to say  from a kind of investment. Unfortunately, one often encounters dishonest sellers who do just the opposite - they cut catalytic converters out of cars and sell them.  .

Auto with a mileage of 265 thousand km. Catalytic converter cartridges whole but already over-fired. Absolutely not a symptom of engine malfunction, normal wear and tear. What else if they were melted or clogged, which is what some customers are counting on, suggesting that now on new inserts there will be a difference in power. And they are right, while melting or clogging of the cartridges does not take on its own and is caused by faulty combustion of the mixture or oil getting into the...

The good old V8. You can see from the design of the manifolds and catalytic converters that the engine is powerful, and it was necessary to design slender backward rushing pipes to fit into the engine compartment, but also, to ensure proper catalytic converter efficiency, the catalytic converters had to be placed right behind the manifolds. Sometimes it's hard to reconcile one with the other, did Audi succeed? Both yes and no ...  .

And it was so nice, American ... ;-)  They drive such in the States Policemen, 305 horses, there is something to chase, although even faster is the 3.5 ecoboost 365 horses. Cool or not it also breaks down and sometimes something needs to be fixed. One of the catalytic converters needs to be replaced. It's a V6 so there are two but one of them was mechanically damaged and at the same time there was a bug for too little catalytic converter efficiency.