What is this part on the cat/downpipe

[fatmonk8]

This "muffler"? Is rattling. But I can't figure out what this part of the downpipe is. I know the two cats are above it. I can't seem to find a diagram stating what it is.

Is it another muffler? Or a resonator?

 

[B-train]

I think that's the big, stainless, flex joint thar bolts to the ball flange. I don't think it's replaceable.

 

[blondie70]

I was told by a muffler guy that it's another cat.

 

[Jeff_]

The California Cat is what that's known as. Useless 3rd cat for California emissions crap.

 

[Thrust]

Yes its a third cat like @Jeff_ said.
Maybe clean it out to stop it rattling.

 

[Rygrego]

This "muffler"? Is rattling. But I can't figure out what this part of the downpipe is. I know the two cats are above it. I can't seem to find a diagram stating what it is.

Is it another muffler? Or a resonator?


View attachment 431235

Downstream Catalytic converter. If it's rattling it's done and must be replaced.

 

[buckwild27]

If you're not in California I would cut it off and put a pipe in it’s place.

 

[fatmonk8]

If you're not in California I would cut it off and put a pipe in it’s place.

I'm in PA, we are CARB compliant unfortunately.

 

[fatmonk8]

I think that's the big, stainless, flex joint thar bolts to the ball flange. I don't think it's replaceable.

No, that's right before the muffler. Others say it's a third cat.

 

[fatmonk8]

Downstream Catalytic converter. If it's rattling it's done and must be replaced.

That's what I was assuming.

 

[fatmonk8]

I just went ahead and bought the Walker Ultra EPA 50497 for a replacement.

It's not CARB compliant technically, but it looks the same and says it will fit. I just can't fathom spending 2k-3k for one that looks exactly the same and will probably perform the same just because it's not CARB compliant.

Just hopefully my emissions shop doesn't check for a CARB #

 

[buckwild27]

I'm in PA, we are CARB compliant unfortunately.

You will still pass i think. There's no 02 sensors on it. It's just a restriction. A lot of people just call it the California 3rd cat.

 

[fatmonk8]

You will still pass i think. There's no 02 sensors on it. It's just a restriction. A lot of people just call it the California 3rd cat.

I actually thought the same thing, that's actually why I asked the forum. I was confused why there would be a cat after the sensors, so I thought maybe it's something else like a muffler or something.

But if I remove it, and I'm in a CARB state, won't that fail regardless because it's missing?

 

[buckwild27]

I actually thought the same thing, that's actually why I asked the forum. I was confused why there would be a cat after the sensors, so I thought maybe it's something else like a muffler or something.

But if I remove it, and I'm in a CARB state, won't that fail regardless because it's missing?

I can’t 100% answer that because I'm in ohio and don't have to deal with it. I would think that PA is not as strict as California.

 

[fatmonk8]

I can’t 100% answer that because I'm in ohio and don't have to deal with it. I would think that PA is not as strict as California.

Yeah, maybe I'll look into it. Maybe I can just have it removed. But I know since my car is newer then 2008 I'm not exempt from the rule. I guess worse case is at that point I just replaced them anyways.

 

[buckwild27]

Yeah, maybe I'll look into it. Maybe I can just have it removed. But I know since my car is newer then 2008 I'm not exempt from the rule. I guess worse case is at that point I just replaced them anyways.

That is true. Good luck! Let us know how it goes.

 

[fatmonk8]

That is true. Good luck! Let us know how it goes.

Thanks!

 

[tom3]

Before spending $2 - 3000 on it I'd neatly gut it and see how it goes through inspection. I doubt they would see any problems with the exhaust, especially if you run it on the highway at speed for some miles before testing.

 

[fatmonk8]

Before spending $2 - 3000 on it I'd neatly gut it and see how it goes through inspection. I doubt they would see any problems with the exhaust, especially if you run it on the highway at speed for some miles before testing.

That's a good idea. I may try that out.

 

[fatmonk8]

Cat gutted, also replaced exhaust with a cat back system. No more rattling. Guess we will see if it fails emissions next time I go in.