Noise from 2nd cat z4 35i

[sjobusen]

I have got some annoying rattle from my 2nd catalytic converter on my z4 35i.

Its like the stuff in the cat is loose....

Anyone experience the same problem and how did you solved it?

Its just the rattle I want to remove... think the cat are working fine...


(Its not wastegate rattle)

[paris1]

Generally, if the innards of a cat deteriorate to the point where they cause noise, the solution is to replace the converter.

[35i-Nut]

are replacement 2nd cats available as its a one piece system?

You could get the exhaust taken off and Cats gutted

Although they would need to be cut out to do this , you may as well weld in some new cats if oem are available , you could refit sport cats if you didnt want the extra noise

[rking117]

Originally Posted by 35i-Nut

are replacement 2nd cats available as its a one piece system?

You could get the exhaust taken off and Cats gutted

Although they would need to be cut out to do this , you may as well weld in some new cats if oem are available , you could refit sport cats if you didnt want the extra noise

Since there are so many sensors on the vehicle i suspect that gutting the cat will give an indicator. Plus if you live in a state that requires emission testing then you will fail it. Plus in most other states where there is not testing of emissions cats are a required so intentionally gutting them may be illegal. The better solution is to source a new cat from GETBMWPARTS.com they seem to be the cheapest place to get OEM parts. I do not represent them but i will give my endorsement of them as i have ordered from them several times.

Note however, if you do have a failing cat that usually means that a larger than usual amount of unburned fuel has entered into it and caused the damage. It could be that its innards were not manufactured correctly but they are designed to last a life time.This may indicate that there is another issue somewhere. I would recommend getting the vehicle tested to make sure that there are no fuel or sensors issues that may be causing this to prematurely breakdown. I would hate to see you replace the cat and only have it happen again in a year.