IndyS200090

When my cat decapitated the second O2 sensor in two years, I read up on the issues with the cat medium breaking loose and sliding backwards. To be clear, the cat still smells like it works fine, it's just that the media has come loose. There seem to be two camps on the issue, the first two involving fixes which keep the original OE cat and the other camp involving various cat replacements

The options I've come across in two days' research across probably 20+ threads:

1) Stick an anti-fouler plug/spacer between the O2 sensor and the cat, call it a day. I've actually seen this posted by Billman a couple of times. My question with this is: has anyone experienced the cat media breaking up further after this? I'm perfectly fine with the occasional rattle. I don't want to have to fish chunks of cat out of my exhaust later on down the line though. If someone can assure me that the cat will be fine like this, this is my preferred solution as I like to keep my S as stock as possible.

2) "Fix" the OE cat. I could have sworn that I saw a thread where the user mentioned that he pinched a segment of the OE cat with a ball joint press or C-clamp to prevent the front core from sliding backwards. I couldn't find this thread a second time though. I would also think a drawback of this is that I risk breaking up one or both cores...something I'd like to avoid.

3) Replace OE Cat with new/used OE cat or OE equivalent. It seems a large proportion of OE cats succumb to this fate and they are quite expensive. I've a few folks here mention an HKS HFC as a more OE equivalent type cat (Certainly judging by the cost, if nothing else) and was wondering about the longevity of that unit. I have no problems spending $800 dollars for something that will work for a long period of time. I just don't want another decapitated O2 sensor in a year or two. I've also seen suggestions of a Mangaflow floating around but several have suggested that will throw a CEL and stock seems spotty.

4) Various other HFCs. I'm talking about all the ones that use (I think) the same the mini/single-core (Ballade, Berk, EVS) and have a CEL fix built into them. I'm extremely skeptical that they will hold up for a long time based on cost alone. On top of that, I've read several threads, not only here but also for other makes (Notably Z cars), where the media ends up blocking the cat partially or totally. I feel like these are a, "You get what you pay for," situation but I'm not totally closed-minded to the possibility.

Additional information:

I have a bone-stock 2001 AP1. I daily drive it and do about 5-6 DEs per year with it. It has about 104k miles on it. I don't have to worry about emissions checks due to where I live but I'm not willing to run a TP because of the stench. My car runs like a top; I didn't have any engine failures which degraded the cat prematurely.

Car Analogy

Mt vote, all of the above.

Look for a low mileage used oe cat. It will have the best quality, at the lowest cost. It will last nearly as long as a new one, for a fraction of the cost.

Meanwhile, while looking, do one of the attempted fixes. The easiest and most certain of which is adding the anti fouler spacer. This only protects the O2 sensor, and doesn't affect the rattling.

You'll just have to live with the rattle until you find a replacement.

Its not difficult to find a low mileage used one, since so many replaced them with a test pipe of hfc early on. As these cars age they are becoming harder to find, but still out there.

A cat from any year S2000 will fit any year S2000. There is a slight difference in O2 sensor placement ap1 vs ap2, but there is plenty of length in the O2 sensor wiring, and you will not be compromising any function or reliability.

Chuck S

My Berk high flow cat has no "CEL fix" gizmo. It's a high low cat, not a cat-delete.


-- Chuck

noodels

Drilled 2 holes in mine,media in the correct position,couple of self tapping screws,and done with out removing from car.

B serious

I'd do something like this.

As another option....

My Berk HFC on my track S2000 has held up perfectly fine for a few years. The cost represents its inability to scrub the exhaust gas as well as the factory cat. My car has a mild stank when starting up. NOTHING like a test pipe...but not like a stock CAT either. It also doesn't smell as clean as the stock one after the HFC has warmed up.

Again...compared to a test pipe car, it smells like roses...but its not as clean as stock.

Deckoz

My Berk has started throwing p0420s after two years/27k miles. And it has the built-in welded spacer. So not sure hfc are a permanent solution.

B serious

Mine throws a CEL, but its on a MY07....so I wasn't really that surprised.

zze86

What makes the 07 special? I is drunk so take no offense.

Chuck S

My '06 has used the 63.5mm Berk high flow cat for 5 years at present with no issues or lights. Not over 20,000 miles though. Hope I don't jinx it.

-- Chuck

B serious

The 06+ tends to not be fooled by defoulers as easily.

My MY07 has a Berk HFC and a defouler with the little catalyst in it. I have a CEL.

My AP1 has a straight up test pipe and just a hollow defouler and no CEL.