Can I remove catalytic converter, remove loose fragments, then put it back on without harming vehicle? I have a 2003 Ford Windstar.

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    – Cullub
    Nov 29, 2018 at 4:17

3 Answers 3


You can, and it won't "harm" the vehicle, but it won't get much better either.

If the catalyst honeycomb is breaking down, the catalyst element is shot, and needs to be replaced. It will continue to break down and result in more "fragments".

Additionally, if the breakdown occurs inside the honeycomb, those fragments cannot be removed without destroying the catalyst entirely. You will have additional backpressure and poor exhaust flow.

Also, think of it this way: Other than the cost of a new cat (aftermarket can probably be had for less than $200) you are already doing the labor to remove the fragments - might as well just install a new cat.

I've completely removed the catalyst part in the past, but this is illegal on a street vehicle in many places and certainly affects emissions.

  • 1
    Couple of years ago while on a trip we had our engine light on and the engine delivering very little power. We had an emergency visit on a small repair shop and since they had no spare parts we had to remove the catalyst, cut open and completely remove the honey comb from inside and re-weld it in place, in order to continue our trip. It stopped the lambda sensor engine warning. The casing was cluttered with these "needles". Still illegal and quite noisy, it had to be replaced when we got back. All these needles are also quite toxic and given the choice any contact with them should be avoided.
    – kokobill
    Nov 29, 2018 at 10:53

I would say it would be a waste of time there are filters in a cat that need to be there. Your just better off replacing the cat if you have it off.


Replacing it is the best option, but if the honeycomb inside looks like it is NOT badly damaged. Then watch this video. Here

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