What is the secondary catalytic converter?

[mp88]

I couldn't help but notice that under my truck, there are 2 cats, a muffler, y-pipe, and then something that looks like a big soup can. Is this my secondary catalytic converter? Does this thing serve any purpose. The reason behind this question is that I was planning on removing the OEM muffler for an aftermarket one. And I wondered if this soup-can thing was actually worth keeping or if I could ditch it for a section of new pipe.

 

[oplitic]

It's the resonator. It just tones down he exhaust, so it's not so loud and whatnot. It's not needed. It's just there for people who don't like loud exhaust. Restriction is all it is really. It cancels out sound waves intern making it quieter.

This isn't how ares looks, but you should get the idea...

'How stuff works' info on it.

 

[IZwack]

Restriction is all it is really.

I disagree, a resonator does not restrict as all it is an open chamber. There are no baffles or any other internals.

 

[aldive]

I disagree, a resonator does not restrict as all it is an open chamber. There are no baffles or any other internals.

Iz is correct.

 

[oplitic]

Iz is correct.

Sorry, I was always told it was. I was still right about the rest of it right?

 

[mp88]

Well at least I know it's not a cat. Haha. Thanks. So if I was to say, remove this piece, it would do nothing but make the truck louder? If I'm barking up an OBDII tree. This wouldn't be such a good idea.

 

[oplitic]

Well at least I know it's not a cat. Haha. Thanks. So if I was to say, remove this piece, it would do nothing but make the truck louder? If I'm barking up an OBDII tree. This wouldn't be such a good idea.

It won't effect OBD, I have mine off, replaced muffler with flowmaster and a down-pipe, no tailpipe.

 

[aldive]

Well at least I know it's not a cat. Haha. Thanks. So if I was to say, remove this piece, it would do nothing but make the truck louder? If I'm barking up an OBDII tree. This wouldn't be such a good idea.

You will be fine; mine has been gone for years.

 

[mp88]

If I recall correctly Al, you have a Flowmaster 70 series. Did you use a catback?

 

[aldive]

If I recall correctly Al, you have a Flowmaster 70 series. Did you use a catback?

Indeed; custom bent 2 1/2" pipe.

 

[GRNMACHINE]

Can the secondary cat be removed without any problems? I am currently running a Flowmaster Force II cat back (50 SUV series muffler) and I would like it to be a little louder. Local muffler place thought the cats are the reason the exhaust is not very loud.

 

[oplitic]

Can the secondary cat be removed without any problems? I am currently running a Flowmaster Force II cat back (50 SUV series muffler) and I would like it to be a little louder. Local muffler place thought the cats are the reason the exhaust is not very loud.

Did they take out the resonator/does the new cat back not have one? If they didn't/ it came with one, than that would be the reason. The resonator is to tone down the exhaust and make it quieter. And the cats should stay on, they get rid of the crap in the exhaust gases. Not to mention it's illegal in almost every state to take them out cause of emissions.

FYI
If you say 'second cat' and are talking about the tube by the rear axle, you should read the thread before you post.

 

[gijoecam]

If you want louder, remove the muffler and/or resonator. Don't say you weren't warned about the ensuing drone on the freeway that's sure to follow. It's generally more noticeable on a Sport. My theory is that the added tailpipe length on the 4-doors eliminates the need for the resonator, so most people that swap exhausts on a 4-door don't have an issue. In my experience, both personally and on this board, removing the resonator causes a drone at freeway speeds.

At any rate, there's no need to touch the cats.

-Joe