Magnaflow Hiflow Cat Vs OBX Hiflow Cat

General exhaust discussion & questions
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By suspendedHatch
- Tue Jan 15, 2013 8:59 pm #324186 Magnaflow cats are crap. They are rebranded from another company so you can't transfer the brand loyalty. I have said this many times on this forum and it is based on my experience owning 3 Magnaflow cats and being an I/M Safety Technician. A Magnaflow cat will get you through a single smog check and you'll fail the very next year. The only exception is on a motor that runs so damn clean it could probably pass without a cat converter at all. I have found that all JDM engines run high NOx.

You're better off with whatever cat the exhaust shop gives you. Weller etc. Stay away from "high flow" gimmicks.

By xhardlinerx
- Wed Jan 16, 2013 4:27 am #324212
suspendedHatch wrote:Magnaflow cats are crap. They are rebranded from another company so you can't transfer the brand loyalty. I have said this many times on this forum and it is based on my experience owning 3 Magnaflow cats and being an I/M Safety Technician. A Magnaflow cat will get you through a single smog check and you'll fail the very next year. The only exception is on a motor that runs so damn clean it could probably pass without a cat converter at all. I have found that all JDM engines run high NOx.

You're better off with whatever cat the exhaust shop gives you. Weller etc. Stay away from "high flow" gimmicks.


Thank you, can you recommend a good brand name that I could buy off ebay? I talked to some exhaust shops and the brands they had were " No name brands" and a "AP" brand (some cheap ebay company) that costed around $100-120.

By rustyrex
- Wed Jan 16, 2013 4:23 pm #324237 go to www.autozone.com and find the cat that is made for your car. in the product description it will say "Direct Fit", write down the part number, then go to ebay and search for that part number. just a heads up i bought my header with cat for my 00 lx at www.rockauto.com for $188. and it is the same exact brand that autozone sells but, autozone wanted like 600 bucks for it.

By xhardlinerx
- Mon Jan 21, 2013 9:28 am #324543 So I looked on autozone and rockauto

Walker Catalytic conveter - 25,000 mile catalytic performance warranty, 5 year warranty on structural integrity. $73.99 from autozone $43.99 from Rockauto. (this looks like a highflow cat)

Another walker catalytic converter, but for $164.00 from autozone or $106.00 from Rockauto - same warranty (this looks like a Non Highflow cat)

Bosal Catalytic converter - $171.00 from Autozone or $121 from Rockauto - comes with 25,000 mile catalytic performance warranty and a 5 year outer shell warranty. (this looks like a non highflow cat)

Catalytic converters from autozone: http://www.autozone.com/autozone/parts/ ... 1ibjZ9ixqf
Last edited by xhardlinerx on Mon Jan 21, 2013 9:34 am, edited 2 times in total.

By xhardlinerx
- Mon Jan 21, 2013 9:33 am #324544
suspendedHatch wrote:Magnaflow cats are crap. They are rebranded from another company so you can't transfer the brand loyalty. I have said this many times on this forum and it is based on my experience owning 3 Magnaflow cats and being an I/M Safety Technician. A Magnaflow cat will get you through a single smog check and you'll fail the very next year. The only exception is on a motor that runs so damn clean it could probably pass without a cat converter at all. I have found that all JDM engines run high NOx.

You're better off with whatever cat the exhaust shop gives you. Weller etc. Stay away from "high flow" gimmicks.


Can you explain why I am better off with what the exhaust shop gives me? Are you saying that even if the exhaust shop has a cheap made catalytic converter, that it will be better or just be the same as a Magnaflow Cat?

Or are you saying that some brands like Weller are much better than magnaflow and will last longer?

Can you please explain why I should pass on a "high flow Cat" and get regular Cat?

THANK YOU
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By teal_dx
- Mon Jan 21, 2013 2:59 pm #324558 The "High Flow" cats that you see on ebay are cheap because they do not always have the proper elements inside to do their full job, compared to an OEM or quality aftermarket cat. Catalytic converters use very expensive/rare metals in the honeycomb element located inside the cat in order to do their job. I don't know the exact science of how they work, but that's why a real cat is so expensive. The "high flow" ones have less or none of the element inside. You get what you pay for :thumb:

Also, 25,000 miles is not much of a warranty. Heck, in Ohio, cars are only required to pass e-check every other year. Average person drives something like 14k mi/yr. You wouldn't even know your cat failed until 2 years later when you go back in for emissions check and your car fails emissions. The OEM cat on my hatch is 20 years old with 180,000 miles and my car passes factory emissions at e-check... WITH a turbo!


You get what you pay for, so if the one you can afford comes with a 25,000 mi warranty... might as well get the cheapest one with that warranty since I don't see it lasting too long. :thumb:
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By kylenjdm93
- Tue Jan 22, 2013 8:51 am #324635
teal_dx wrote:The "High Flow" cats that you see on ebay are cheap because they do not always have the proper elements inside to do their full job, compared to an OEM or quality aftermarket cat. Catalytic converters use very expensive/rare metals in the honeycomb element located inside the cat in order to do their job. I don't know the exact science of how they work, but that's why a real cat is so expensive. The "high flow" ones have less or none of the element inside. You get what you pay for :thumb:

Also, 25,000 miles is not much of a warranty. Heck, in Ohio, cars are only required to pass e-check every other year. Average person drives something like 14k mi/yr. You wouldn't even know your cat failed until 2 years later when you go back in for emissions check and your car fails emissions. The OEM cat on my hatch is 20 years old with 180,000 miles and my car passes factory emissions at e-check... WITH a turbo!


You get what you pay for, so if the one you can afford comes with a 25,000 mi warranty... might as well get the cheapest one with that warranty since I don't see it lasting too long. :thumb:






THE CATYLITIC CONVERTER gets superheated by the exhaust temperatures created by the engine, the elements in the cats are heated like a coal furnace, the CATYLITIC CONVERTER (not a feckin Cadillac converter) burns off the excess HYDROCARBONS produced by the engine combustion process. O2 sensors require the use of the CATYLITIC CONVERTER in order to determine how efficiently the engine is running.

people always say "remove the cat you don't need it" it all depends on your tuner, if a tuner cant tune my car with my 3" cat then obviously he is not as skilled as I was led to believe

MAGNAFLOW is a shit brand, a walmart brand sams club line of FLOWMASTER. from what I was told by a friend who owns and exhaust shop. lol

hope the info helps I could get further into detail. if you would like to know the actual facts with scientific explanations ask me.
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By teal_dx
- Tue Jan 22, 2013 2:04 pm #324638 Is it the rare metals (palladium, rhodium) inside that get the job done or make the cats last longer? Do the cheaper ones use a less expensive material inside?
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By Apexracing
- Tue Jan 22, 2013 3:01 pm #324649
xhardlinerx wrote:So I looked on autozone and rockauto

Walker Catalytic conveter - 25,000 mile catalytic performance warranty, 5 year warranty on structural integrity. $73.99 from autozone $43.99 from Rockauto. (this looks like a highflow cat)

Another walker catalytic converter, but for $164.00 from autozone or $106.00 from Rockauto - same warranty (this looks like a Non Highflow cat)

Bosal Catalytic converter - $171.00 from Autozone or $121 from Rockauto - comes with 25,000 mile catalytic performance warranty and a 5 year outer shell warranty. (this looks like a non highflow cat)

Catalytic converters from autozone: http://www.autozone.com/autozone/parts/ ... 1ibjZ9ixqf


Walker makes quality oem parts, I've bought walker eg exhaust parts before, and i will again for my ej1.

By rustyrex
- Tue Jan 22, 2013 3:37 pm #324654 Teal you are correct. the precious metal use as the core of the cat is what gets the job done. when they are warm or heated if you will there is a chemical reaction between them and the core substrate that esentially becomes a filter for hydrocarbons, Nox gas and other green house gases. basically the heat from the combustion process "excites" the atom in the precious metal and their reaction to being excited (giggity) is to filter whatever passes through them.
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By HagerSol
- Wed Jan 23, 2013 9:36 pm #324800 Might get lucky at a junk yard but some of those places rip cats and rims as they come in. A used oem cat from a Japanese or German car will prolly be better than anything magnaflow or flowmaster sell. Good luck!
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By Apexracing
- Thu Jan 24, 2013 4:07 am #324829 Thinking of going with an obx stainless header for my ej1, if i cant find a used header for it.
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