Welcome to the "it happens to many of us with S2Ks" group! The internals of the OEM cat break loose for a variety of reasons and can be forced back hard enough to shear the sensor tip off, as you found out.

I run a Skunk2 cat-back with a custom stainless steel header. Honda USA told me to get lost as "your aftermarket exhaust system destroyed the cat and we will not help you."

Living in the People's Republic of California, I found a CARB-legal high-flow cat from Berk Technology (http://www.berktechnology.com/shop/p...D=100&P_ID=425). According the Berk, it flows nearly 85% as much air as a straight pipe, but passes smog in CA. I would suppose the shipping to you would be prohibitive. Good luck!

 

O2 CEL fix.. never heard of it until now thanx! found 1 one ebay and it said a simple screwed on to existing secondary 02 sensor.

If i order the O2 CEL fix, Does this mean i do not need to order a new O2 secondary sensor to replace the one that was broken because of the honeycomb sheared off the secondary oxygen sensor?

Can the O2 CEL FIX able to install in the original CAT without a honeycomb or i still need to make a new test pipe in order for the CEL to go away?

Please help..

 

You still need the new sensor, But you won't need to install the testpipe if you don't want to. It would probably net you more power tho. If you order the CEL fix order two just in case. Sometimes it takes more than one to get rid of the CEL.

 

thanks N2OexpressS2k..
i have decide to get a test pipe since it seem to be the best solution for long term.. can you or anyone advice me which of the two test pipe is better for my HKS hi-power dual exhaust? Do both comes with CEL fixed?
Mugan Racing Testpipe or Berk Technology testpipe?

http://www.tcsmotorsports.com/exhaust3.html

And also any recommendation for which brand secondary O2 sensor

thank alot

 

Go with the berk. Looks like their new test pipes have the CEL fixed welded on already.

 

Just found this as well:




I guess I'm on the hook for a new O2 sensor, but the cat is covered under the 8/80 warranty, right? Then again, since the cat damaged the sensor, maybe that's covered as well...

 

No need to buy a testpipe at all! Just take all internals out of the Cat, and put that in.

Buy the new good O2 sensor, and a couple of spark plug anti-foulers. They are what essentially test pipe CEL fix is. Just match the thread.

And you're good to go!

https://www.s2ki.com/forums/index.php?showtopic=633925
This is what the spark-plug anti-foulers might look like in your local auto parts store.


https://www.s2ki.com/forums/index.php?showtopic=633006
This has some description on how to put them in properly.

 

TP for the win lol

 

so now i don't need a test pipe??? i am
alright so i buy new good O2 sensor, and 2 of spark plug anti-foulers to fit in the CAT without honey Comb inside and is will removed CEL for long term? better than just get a new test pipe with O2 CEL fix correct?

The link you sent on how to put them in properly is for test pipe not for CAT

your post:
The one that goes into the TP is not modified. The second one, that goes into the one that is already in the TP, has to be drilled out to make sure the hole can accomodate the tip of O2 sensor, since the tip of the O2 sensor might be too long for the anti-fouler:

|=| is the hexagonal part
=== shaft, and - is the tip with the little hole.

O2 sensor -> |=|===- -> |=|===- -> TestPipe O2 Bung
__________________ ^
__________________ ||
__________________ this gets drilled

Can you tell me as simple as possible on how to do this on the original CAT ? .. just so i know what to do exactly...

 

Right. Hollowed-out original cat is exactly the same as the test-pipe. Only difference is it has OEM fit and quality. Looks kinda ugly compared to a beautiful test-pipe, but how many girlfriends yo gonna impress with that? Bend them over to show them the TP? Sorry, getting kinda wrong.

To do it, follow the diagram. Once you get the parts, you'll be able to figure it out pretty easy.

The whole idea is to keep the gases from hitting the secondary O2 sensor head-on, like originally intended by manufacturer.

The cat is supposed to burn up the exhaust gases. The ECU (engine control unit) compares the readings on the 2 sensors. the secondary sensor's reading is supposed to be 'cleaner' since it's just passed through the chemical-reaction-inducing honeycomb of the cat. In other words, the cat's honeycomb internals change the exhaust gas to be 'cleaner'

ever drive behind a really old truck that smells something awful? guess what, they got no cat. U.S. laws don't require really old vehicles to have a cat. So your exhaust gas will smell worse, don't run the car in your garage, not even for a minute.

The TP CEL fix (or those 2 or even 3 spark plug anti-foulers) do is take the secondary O2 out of the direct exposure to the exhaust gas. Why? The computer needs to 'smell' that the secondary O2 sensor is getting a 'cleaner' gas, as compared to the primary (first) O2 sensor.

But since you don't have a cat anymore, (ok, you do, but it's empty inside, has no honeycomb), and in effect the empty cat is the same as TP, the gas that hits the secondary O2 has the same chemical composition as the gas that hits the primary O2.

When secondary O2 is out of the direct stream, hiding inside that TP CEL-fix/SPlug anti-fouler, it's not able to sniff as much gas, therefore reading lower number on the 'bad' content of the exhaust gas, therefore in effect tricking ECU into thinking that there actually is a cat, and that it actually is working properly. That's it. So just mount that O2 sensor behind that hole in the TPCEL-fix/SP A-F.

Check sparkplugs.com for a universal secondary O2 sensor.