Misfiring led to the complete destruction of the catalytic converters, specifically their ceramic inserts. What does not burn in the cylinder chamber will burn in the catalytic converter, damaging it. It may be fuel due to leaking injectors or misfiring, or it may be oil due to an oil defect. Whatever it is, it's not good for the catalytic converter. Interestingly, the catalytic converters looked intact from the outside and someone judging only by their appearance using an endoscopic camera inserted through the lambda probe socket could say that they are OK. However, the real tragedy occurred inside the inserts, which in some places were completely melted, with no capacity, resembling solidified lava. 408 horses and not running, no wonder, since 30% of the original capacity remains. By the way, a few months ago we had an even better case - the catalytic converter was so clogged that the automatic transmission did not want to change gears because it could not reach the desired rpm.

The original throughput of these cartridges is 600 cpsi and we assume the same, with the difference that we use metal cartridges that are more resistant to mechanical damage. The model is 2010, so Euro 5 standard. We cut the catalytic converters, remove the remains of the original inserts, and weld in new inserts -

https://kat-eko.com/pl/uniwersalne/390-2366-wklad-katalizatora-benzyna-awg.html#/51-srednica_wkladu-130_mm/58-norma_euro-euro_5/65-przepustowosc_cpsi-600/72-dlugosc_wkladu -80_mm

and we weld the housings. Two hours and the catalytic converters are delivered to the customer.

Identical catalytic converters are found in cars with N63B44 and S63B44 engines:

• BMW F07, F10, F11 550i, 550ix

• BMW F12 650i, 650ix

• BMW E70 X5 50ix, X5 M

• BMW E71, E72 X6 50ix, X6 M

• BMW F01, F02, F03, F04 750i, 750 Li, 750 Li x

OE original number:

• 18327645234

• 18327645235

• 18307576993

• 18307576994

1. before regeneration

2. after cutting

3. damaged cartridge

4. removal of damaged cartridges

5. fitting new cartridges

6. housing welding