When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So I just took my car to a muffler shop and cut out my secondary catalytic converter. I have 2013 r56 JCW.
To everyone’s surprise there is nothing in the catalytic converter! The thing is literally just a straight pipe with the outward appearance of a catalytic converter.
my problem is I just paid someone to remove this, when this could have been very beneficial to me, as I live in California, and recently passed smog testing as well. The straight pipe they now added is making an odd sound, probably due to bad welds? or the material?. Any idea what it is or what I should do? Kind of a bummer I just cut out the secondary cat all for it to just be a straight pipe anyway.
Nah it is the secondary catalytic converter. I’ve had the resonator and muffler previously deleted. I’m curious if anyone has had a similar issue where the contents disappear inside of it.
Are you the original owner? If not, the previous owner probably hollowed it out and left it installed to make it “Look” like it had the second cat…. That would be my guess
So I just took my car to a muffler shop and cut out my secondary catalytic converter. I have 2013 r56 JCW.
To everyone’s surprise there is nothing in the catalytic converter! The thing is literally just a straight pipe with the outward appearance of a catalytic converter.
my problem is I just paid someone to remove this, when this could have been very beneficial to me, as I live in California, and recently passed smog testing as well. The straight pipe they now added is making an odd sound, probably due to bad welds? or the material?. Any idea what it is or what I should do? Kind of a bummer I just cut out the secondary cat all for it to just be a straight pipe anyway.
Yep, that’s normal. the secondary “cat” on these is basically a dummy. If the new pipe sounds off, I’d take it back and have them check the welds or swap to a resonated section.
Yep, that’s normal. the secondary “cat” on these is basically a dummy. If the new pipe sounds off, I’d take it back and have them check the welds or swap to a resonated section.
interesting to say the least. I got faked out by own exhaust lol. I’m going to take it into the shop later this week, maybe change the piping diameter all the way through.
No, nope, wrong. The secondary cat is NOT fake or empty or a "dummy" cat.
Take a look at this picture of OEM stock mid pipe:
In this picture, the left side is where it clamps to the down pipe. (For the OEM system, the primary catalytic converter is in the down pipe. The cat in the down pipe is monitored for engine operation by the two O2 sensors.) In the picture above, exhaust flows from left to right. The right end in this picture connects on to the rear muffler. Again, moving from left to right, the components are as follows: flex pipe, secondary cat, resonator. The resonator is a flow through device, and is "empty" when looking through it. The secondary cat is NOT empty, but has catalyst materials inside, just like the primary cat in the down pipe. If your secondary cat is "empty," someone did something to it - either replaced it or hollowed it out.
No, nope, wrong. The secondary cat is NOT fake or empty or a "dummy" cat.
Take a look at this picture of OEM stock mid pipe:
In this picture, the left side is where it clamps to the down pipe. (For the OEM system, the primary catalytic converter is in the down pipe. The cat in the down pipe is monitored for engine operation by the two O2 sensors.) In the picture above, exhaust flows from left to right. The right end in this picture connects on to the rear muffler. Again, moving from left to right, the components are as follows: flex pipe, secondary cat, resonator. The resonator is a flow through device, and is "empty" when looking through it. The secondary cat is NOT empty, but has catalyst materials inside, just like the primary cat in the down pipe. If your secondary cat is "empty," someone did something to it - either replaced it or hollowed it out.
oh shoot, I think the secondary cat must of been cut out, It must be the flex pipe off that I took off. What is the function of this piece?
The flex pipe section allows for movement of the exhaust and to prevent any cracking.
thank you just figured that out 😩. Just got a new flex pipe and tips installed for a pretty good deal I’d say. They told me get the downpipe and we do that too, man LA is wild.
The early N14 JCW cars had a large resonator with no second cat. Those early cars also had a multi-cell cat in the down pipe. Then, at some point maybe mid-2010, Mini switched to a second cat with smaller resonator, and kept that set up moving forward. Later N18 JCWs had the same down pipe and exhaust as S models, with the exception of the rear muffler. Seeing as his car is a later N18 JCW, his car would have shipped with the second cat configuration.
The early N14 JCW cars had a large resonator with no second cat. Those early cars also had a multi-cell cat in the down pipe. Then, at some point maybe mid-2010, Mini switched to a second cat with smaller resonator, and kept that set up moving forward. Later N18 JCWs had the same down pipe and exhaust as S models, with the exception of the rear muffler. Seeing as his car is a later N18 JCW, his car would have shipped with the second cat configuration.
I stand corrected.
I was going by my (2009)
N14 JCW R55 which doesn’t
have one.
I forgot that they changed it later.
