E46 B3 3.3 - Catalytic converters

[sat82]

Hi all,

I searched but couldn't find a thread about this, so apologies if there already is one.

I may have an issue with my Cats so just wanted to double check, if the Cats are specific Alpina parts or stock BMW?

I know the centre and back box are specific Alpina and probably the exhaust manifold too, but I'm not 100% sure about the Catalytic converters.

Any help would be appreciated.

Regards

[Adwo]

They are Alpina specific, made by Boysen. They very rarely break as they are the metal versions. You could have someone weld in new cats in the existing pipes. I would seriously consider that as I fear the original ones are really expensive..

They do make some strange noises right after start up as they are warming up and the double skin is expanding. If you put a small screw between the 2 layers the noise is gone..

HTH,

Adwo

[sat82]

Many thanks for your reply Adwo.

Thankfully I was informed yesterday afternoon the issue I'm getting is not related to the Cats and more likely engine side.

Kind regards.

[Adwo]

I hope you this can be corrected without breaking the bank. Engine side just doesn’t sound cheap to me..

[sat82]

Lol, indeed.

Potentially it's the hydraulic lifters. So oil drain, rocker cover off, timing chain off, vanos off, cams lifted etc.....

I've spent thousands over the last 7 years of ownership on keeping her running tip top, so looks like she still wants more thousands spent to keep her happy