Catalytic converter for a 99 Subaru

The catalytic converter on my 1999 Subaru Legacy rusted and, following a bump on the highway, detached from the rear portion of the exhaust system – see the attached photograph. Any thoughts on how to repair this? Can I have it welded back together? Or do I need a whole new converter? If so, how much can I expect to pay?

Your advice is most welcome!

You can’t weld on rust.

I think the cat will be fine. But it looks like the exhaust needs to be replaced from the cat back.


But isn’t the cat the part that’s rusted and detached? Everything from the bolts in the middle of the photograph to the back of the car was replaced less than a year ago…

Assuming the left side of the picture is the front of the car (it’s a little confusing), they might be able to cut back the short section of rusted pipe and if there is enough meat at the converter they might be able to weld in a new section of pipe & flange. What makes the picture confusing is that the downstream O2 sensor isn’t always mounted directly on the converter.

Yep, the left side is the front if the car—sorry for the confusion. I may be mistaken but I believe the cat is on the left and the resonator is on the right.


I’ve never seen a cat rust like that. And I live in Minnesota!

The cat requires replacement.


Yeah - it looks pretty nasty but it needs a closer look.

Dang. Any idea about what I can expect to pay?

That’s the rear cat that’s rusted.

Does the cat system look like this?

Or does the rear cat mount to the front cat like this?


The really bad section of pipe looks like it isn’t even stainless steel. If the converter itself is stainless steel and they can cut it off flush they may be able to patch a new piece in. I had a new flex pipe patched in on my wifes Pontiac G6 recently at Midas recently for $250. They did a great job. This would be quite a bit simpler. But more than likely they’ll want to replace the converter as tester says.

I’d take it to a muffler shop and see what they can do. Be sure to wire up the resonator so it doesn’t drag.

Lots of rot there. Any repair will be temporary at best.

The only possibility would be to cut the pipe end square, cut the bolts and pull off the front part of the flange joint, put a split flange, splice, and metal gasket in, and bolt it back together. Assuming that the area doesn’t just crumble with the attempt. Then next week, when another spot comes apart, you’ll have had practice in Mickey Mouse exhaust repairs.

Tester: the rear cat mounts to the front cat (as in the second link you posted). I presume that’s better, as it means they won’t have to replace the whole system – is that right?


The rear cat is the only one that needs to be replaced.

A lot cheaper!