In today's article I would like to touch on the subject of catalytic converter regeneration for BMW E39 540i V8 car. I recently had the opportunity to perform such a remanufacture, and today I will share with you information about it.

1. Introduction

The catalytic converters I received for remanufacturing turned out to be empty. Unfortunately, I can't tell much about their condition before regeneration. There are several possibilities - maybe the cartridges were already cracked and buzzing inside the housing, or the customer decided that without catalytic converters his car would sound better and have more power. However, nothing could be further from the truth. A car equipped with a naturally aspirated 4.4-liter V8 gasoline unit, as in this case, requires adequate pressure in the exhaust system, which is provided by catalytic converters.

2. Effects of empty catalytic converters on car performance

Empty catalytic converters do not have a positive effect on car performance. On the contrary, the result of such a situation is an ugly metallic resonance sound that resembles the sound of a Polonez or Fiat 125P engine. The hollow chamber that is created when the catalytic converter is "gouged out" causes the sound to resonate and makes the car sound unpleasant.

3. Choosing the right catalytic converter cartridges

If indeed the catalytic converters were worn out or cracked, there are two solutions, depending on the customer's preference. If one wants to preserve the original engine performance, the best solution is to use 400 cpsi capacity cartridges, as in the described model. Alternatively, you can opt for 200 cpsi capacity sport cartridges. These represent a golden mean between the original 400 cpsi catalytic converter and the over-through (used in rally cars) 100 cpsi or no catalytic converter. Cartridges with a higher throughput will allow for increased exhaust gas flow, which will contribute to more power.

4. Maintain original engine performance

It is worth remembering that sports cartridges, due to the smaller surface area of the catalytic core, perform less well in maintaining the emission standards that by design should be met. Therefore, when deciding on a sports catalytic converter, it is worth considering a catalytic converter designed for a larger engine capacity. Maintaining the original engine performance is important to maintain optimal performance and compliance with emission standards.

5. Catalytic converter cartridges used

In the case of the subject unit, cartridges with a standard 400 cpsi capacity and Euro 4 emission standard were used. They have a diameter of 110 mm and a length of 100 mm. Originally there were 4 inserts, 2 per side, but for financial reasons the customer decided to weld in only two inserts, one per side, which was enough to correct the error of low catalytic converter efficiency. This demonstrates the good quality of the inserts, which meet the relevant emission standard and are effective despite the reduced catalytic surface area.

The catalytic converter inserts that were used in the subject unit can be found at the link: Universal Euro 4 AWG catalytic converter cartridge

Alternatively, there are also sports cartridges that can be used on this model, which have a capacity of 200 cpsi. They can be found at the link: Euro 4 AWG sports catalytic converter cartridge

In summary, catalytic converter regeneration for the BMW E39 540i V8 is an important process that affects engine performance and emissions compliance. Choosing the right catalytic converter cartridges is crucial to maintaining optimal vehicle performance.