feuss2

iTrader: (1)

I've been reading up on aftermarket cats, made a few observations, and have a few questions....

Observations:

The reason people are doing this is for increased torque/power and/or throttle response.

One manufacturer of aftermarket cats claims that cats are not the horsepower killers they used to be, and that their high-flow cats would have only a negligible performance difference from a test pipe.

An alternative solution is to use a "test pipe" which just replaces the cat with a straight length of pipe. This normally results in a check engine light (CEL), but you can avoid this condition by using one or more spark plug anti-foul adapters to move the second o2 sensor away from the exhaust stream. * Topic for further reading: What is the CEL for? Why does this fix it?

The CEL codes that came from using test pipes indicated that the ECU "knew" the cat was not functioning properly. The simplest explanation I was able to find was that there are 2 oxygen sensors, one before and after the cat. If the cat is working properly, the second sensor should see a lower oxygen content in the exhaust then the first because oxygen is consumed in the reaction taking place in the catalytic converter. With a test pipe, the readings are the same, so it looks like a malfunction to the ECU.

The spark plug anti-foul adapter is a spacer intended to relocate a spark farther from a source of oil or other contaminants that would normally foul a plug. (A cheap fix for an engine with a bigger problem?) They happen to be made in a size/thread pattern that's the same as many o2 sensors. So people have figured out that if you stack up one or more and use it to move the second o2 sensor farther from the exhaust stream the CEL does not come on. I could only find several speculations as to why this works, all having to do with trapping exhaust (carbon monoxide (co) and carbon dioxide (co2)) gasses around the second sensor.

Many people with Random Tech cat's are getting CEL's as well.

Some Random Tech users that had CEL's installed one or more anti-fouler adapters, cleared the codes and they did not come back.

Fastline Performance is now offering a product that is an "improved" version of the RT, seen here: https://acurazine.com/forums/showthread.php?t=697022


Note this difference between this picture in the original product announcement:



...and this picture found in the sales thread that followed:



I called Carsound/Magnaflow and asked specifically about using the spun ceramic cats in a 2.4L 4cyl NA application a few months ago. The person I spoke to said that these were designed for higher displacement engines, and used in a 2.4L NA engine would never get hot enough to work properly.

Questions:

Does anyone here have more information regarding why the use of the RT cat results in a CEL? And how/why the use of the anti-foul adapter suppresses the CEL?

Are the spun ceramic cats really cleaning up the emissions?

Or are they basically cats that flow really well because they are over-sized for the application, which are actually functioning more like test pipes than cats?

Has anyone that has access to an exhaust sniffer actually tested these cats and can say how clean they really are?

lcrazyaznl

iTrader: (1)

I get a cel on my magnaflow highflow cat. Just randomly, same code p0420 just fell below the limit.

I just clear it since the cat was checked out already a few times.

MrHeeltoe

iTrader: (1)

Thanks for asking!

Here are my answers:


The RT cat produces a cell primarily because it has a lower cell count in the core than the OEM and therefore reduces the emissions less than a stock cat does. While it performs well as a high flow unit it does not perform as well as stock in terms of gas conversion. The same is true for the FLP cat. It may be debatable as to where the bricks in the RT cat come from and therefore what the QC of the precious metal slurry is we don't really know.

A cel eliminating devise like the "defouler" (*thanks for blowing a hole in this. It is a peeve to me when people call it an O2 defouler. It is a spark plug defouler in a 2-stroke motorcycle engine, and as a matter of coincidence it is a O2 senor reading inhibitor on a car). is used to prevent a cel for occuring, which apparently does not always work.

The Fastline Performance (FLP) cat initially had a standard O2 bung on it but then we put an extended one on there to reduce the risk of a CEL. While a defouler will move the O2 sensor away from the exhaust flow it also has a small hole at the end which restricts gas access to the O2 at all. We have tried to make the setup on the FLP cat the right parameters to allow it to see just the right amount of exhaust. If the second O2 (the "cat-checker" if you will) sees too much (OR TOO LITTLE) emissions gasses then it will trigger a light. Defoulers can tend to shield the O2 a little too much.

The bottom line is, you need the engine light off in order to have the engine running optimally. And that's why you need to use one.

The FLP cat is designed to prevent you from needing to buy something else later.

A spun body, a welded body, , stamped or formed, blah blah blah....it is just the method of production that forms the cat's body. A spun cat is nice because it is an effective way of holding the converter bring in place and necking to inlet and outlet down to exhaust-piping size. It is all one piece. Compare it to the multiple pieces that the RT cat has. The emissions conversion of a cat nothing to do with how the body is made and everything to do with cell count of the substrate and the quality of the precious metal slurry applied to the substrate.

These cats are not oversized. I don't know who you were talking to at Magnaflow, but this is not an oversize cat for this car. Pretty much every converter Magnaflow lists is suitable for a small engine or one bank of a larger engine. I see upper limits on engine size but not lower limits. I installed the FLP cat on the test car and started it. Within seconds of idling the cat was hot. Getting up to operating temperature is a non issue with the FLP cant and also the Random cat. If these cats are unable to convert gases on these cars at all it is largely due to the lesser cell count (thereby lesser surface area inside the cat) of the core. In other words, the cats are too "small" not to big.

The high flow nature of the converters is provided by that lower cell count though. And there we find that a compromise is met. While a true straight pipe will provide similar or slightly more power gains than a high flow cat, they also will increase the noise as the converter brick will muffle the exhaust sound a little.

And so as not to completely bitch-slap the environment they do convert exhaust gases and provide lower emissions than with no cat at all. They just don't convert them quite as much as that second O2 would like to see. Really these small cats are better used as PRECATS.

http://www.car-sound.com/02product/u...al/599spun.asp

Look at these tiny cats being used on engine UP TO 5.2L-6.2L. I don't buy that at all. An engine that size would use this as a precat and then would need another cat farther down the line to really clean the exhaust.


No. We, I haven't anyway. But we aren't making these to pass smog. We are making them to increase power. Magnaflow (Carsound Exhauist, Inc.) DOES mix their precious metal slurry in house and employs a full time chemist (her name is Bindu ) to monitor the mix for QC. And then they test a few bricks from every batch on a real live test car on a mustang dyno to make sure the cats do convert emissions properly. In general we say Magnaflows are effective at converting emission gases.

Marcus

JTso

iTrader: (2)

Here's a comparison of a high flow cat (200 cells) and a test pipe of the same dia (2.25"). According to the data collected, It's possible to have a cat that flows like a test pipe and not trigger any CEL, even without any additonal defouler. Not sure about how clean is the exhaust gas though.

The blue in the chart is the test pipe and red is the high flow cat.

Excelerate

iTrader: (1)

Unfortunately, test pipes tend to create a very raspy exhaust note. That is why it is better to run a high flow cat since you really don't sacrifice much exhaust flow. The reason the RT cat, or for that fact any aftermarket high flow cat, sets the CEL P0420 for Catalyst Efficiency Below Threshold, is because the ECU has very strict parameters as to how much flow it wants to see. When the cat flows too much exhaust and the secondary 02 sensors see this it thinks the cat isn't doing its job and it triggers a CEL. This doesn't mean your cat is bad; it means it flows too much for what the ECU wants to see since it's basing its info off the stock cat.The easy way to solve this is to install a CEL eliminator in the secondary 02 sensor bung:

http://store.excelerateperformance.c...x/g-53427.aspx

This basically pushes the 02 sensor further away from the exhaust stream and allows the 02 sensor to think the cat is doing its job as it wants it to.

On a side note, both the RT cat and the Magnaflow spun cat are both 300 cell so their flow is the same.

1slwTSX

Wow looking at the dyno graph, looks like just 1 hp difference. I would definitely run the high flow cat just so you dont get that raspy test pipe sound. Plus that way you can still be so called "legit" in CA because technically you are still running a cat.

valeratj

It was mentioned before that today catalytic converters are not power killers like they used to be. Someone on this forum wrote that after he had a SC, header, CAI and a few other mods, high flow catalytic converter gave him 9 WHP.

MrHeeltoe

iTrader: (1)

An O2 sensor is not a flow meter. It is a devise that measure the amount of oxygen in a gas mixture. The cel get set off because the sensor detects gas readings outside what the ecu considers to me an acceptable range.

The "defouler" and the extension on the FLP limits the O2 sensor's exposure to the exhaust gas, thereby limiting the amount of unconverted gas it sees. With a high flow cat of this caliber (either FLP or RT), the exhaust is not being converted enough and the ecu thinks the cat is not working properly.

And before we settle this cell count issue, we still are doing research. I still hold that the Magnaflow cat has 200 cells. Whether the claims are correct or not, the cores visually show the Magnaflow being more open, and the piping on the FLP cat is larger as well. This cat will ultimately flow more than a RT one.

Marcus

xjohnkdoex

iTrader: (2)

any updates regarding the cell count comparison?

MrHeeltoe

iTrader: (1)

The only dispute seems to be between Josh's sources and mine. Both sources work for Magnaflow. Mine is an engineer who specialized in brick sales who says they are 200 cells, and Josh's are performance component sales people who say they are 300 cells. Also, the deductive reasoning in my other threads seems to indicate the MF is 200 cell count.

That is basically the end of it. :/ To me, I am sticking with the 200 cell count on the FLP and the 300 cell count on Random.

Marcus

JTso

iTrader: (2)

I just received a Magnaflow metal core cat yesterday for my Prelude so I decided to make a quick comparison with my 200 cell Metal cat. The cat is the same 59950 series as the Fastline. Mine is 59956 for 2.5". However, mine has an strange coating all over the core which is very different than the Fastline one. Not sure what the coating is...

I'm not sure what's the correct way to measure cell counts on a metal core cat. So this is more of a spacing comparison and I reserve the rights to be completely wrong.

Both cats have the same dia. core and length. I placed an one inch piece of wire over the cells approx. eight rows from the center on each cat and count the hole spacing.

Magnaflow metal core cat




Metal' cat

xjohnkdoex

iTrader: (2)

that's cool, i was just curious if anyone ever found out the official cell counts. i think i'm planning to mod my header, and i'm pretty tempted to do the cat at the same time and just get it all done at once. so i'm just trying to weigh the options available based on the information out there.

godfather2

^ if you're doing the header, might as well do the cat at the same time! you'll love the difference

xjohnkdoex

iTrader: (2)

that's what i'm thinking! i doubt my wife will agree. LOL.

godfather2

^ it's really not that much more $ and the exhaust note will only increase a bit

LukeaTron

That coating is the metal slurry that actually contains the catalyst media. The amount of slurry applied has a big effect on the amount hydrocarbons that are converted. The new one looks like it should be a lot more effective in that arena but I have to wonder if it's not going to be more restrictive as a side effect.

JTso

iTrader: (2)

^^
That would be my guess as well. Just that I haven't seen such coating on other oem or aftermarket cats.

MrHeeltoe

iTrader: (1)

A note on cell counts: It has become apparent there is a debate on how many cells there are in a Magnaflow metal core cat. Some say it is 200 cells, others say it is 300 cells. We can conferred with Magnaflow Engineers and have come to the conclusion that neither claim is actually true. Due to the concentric (circular) construction of the metal cores, the cells in the center are actually a different size than those toward the outside of the core. Also, due to the thin and flexible nature of the material used to make the cores, production inconsistency causes variable sizing. As such, Magnaflow largely advertises the cores as 200 cells while in reality many are closer to 300 cells. For this reason, we now claim a 250 AVERAGE cell count for Fastline Metal Cats using Magaflow cores! The cell count is relatively moot because no matter what the actual cell count is in an FLP core, it is significantly lower than that used in the OEM cat and will provide significant power gains even without tuning! Additional flow is provided by larger inlet/outlet sizes.

Benz_05_TSX

iTrader: (1)

Wow...great debate...

So RT CAT is not as good as the other ones eh?/...

msmching

i thought the conclusion is... FLP CAT > RT CAT already?

thats y i went for the FLP.. lol.

carmagnut

Any CEL's with this Cat? How long have you had it on the car?