Stock Catalytic Converter vs. No Cat vs. High Flow Cat

[sonni_kuba]

This is something that I've been contemplating for a long time now. We all now that removing a catalytic converter will get you improved exhaust flow, power, torque, etc. BUT HOW MUCH MORE

I came across this neat little article that you may find useful.

http://www.importtuner.com/tech/impp_0610_catalytic_converters/

These guys did dyno pulls on a 1999 Civic Si with an aftermarket intake, header and cat-back exhaust system, under four conditions

1) Stock Cat
2) Magnaflow Ceramic-core high flow catalytic converter
3) Magnaflow Metallic core high flow catatytic converter
4) Catalytic converter deletion

The results, in case you don't want to read the entire article ....

1) Stock Cat - 147hp/105 lb-ft to the front wheels
2) Magnaflow Ceramic-core high flow catalytic converter - 150hp/107 lb-ft
3) Magnaflow Metallic core high flow catatytic converter - 151hp/107 lb-ft
4) Catalytic converter deletion - 152hp/108 lb-ft

There you go, these results were actually better than I expected. Definitely going to go with the high flow cat vs. catalytic converter deletion route.

 

[20-CG5-01]

Depending in some states countries, running no cat/gutted cat/test pipe will not be allowed in your area.

Beware, running cat will make your car stink so bad if you stand behind it.

In california, it's illegal to run a car with no Cat, if you do get pulled over for it by the cops and they find out you're not running a cat, you'll get a huge fine.

Nice find, but I believe in the stock f23, a oem cat/high flow/gutted wouldn't result in such a big performance, but more sound.

 

[H-town_Ryda_06]

High flow cat FTW

My butt-dyno says the high flow made a pretty big gain in hp for me
I wonder what the gains are in v6 vs i4

 

[soccerchamp16]

I have the V6 with a magna flow high flow cat, idk which one it is I got it a long time ago. I noticed some gain but nothing ridiculous

 

[sonni_kuba]

Depending in some states countries, running no cat/gutted cat/test pipe will not be allowed in your area.

Beware, running cat will make your car stink so bad if you stand behind it.

In california, it's illegal to run a car with no Cat, if you do get pulled over for it by the cops and they find out you're not running a cat, you'll get a huge fine.

I am pretty sure, it's like that in the whole Western world. I agree, running no cat would be a huge risk, but thanks to this article, there's really no point if you can get a high flow cat.

 

[Lebowski]

My oem cat had some of the plates break loose inside, it was horrendously loud and more restrictive. I purchased a "testpipe" of cheapBay for less than $30 as a stop gap measure while I gathered some extra coin and scoped out my options.

It's been 6 months now and im totally cool with it. I have no CEL. Did the plug spacer trick. Noise is a non issue with the catback set up I fabbed up.

Smell wise its not too bad. If your car is in good working order it shouldn't smell like a burning oil refinery. It's stronger smelling than normal but it doesn't smell like the *** end of a clapped out 40 year old motown bigblock. It was fine in the summer heat with the windows down. Its fine now with the windows up and the heat on.


I live in central Wisconsin. 1 out of every 3 trucks have pseudo diesel smoke stacks in the bed behind the cab. The Cops really don't care. I live 10 mins away from Road America. Guys dont typically get harassed for their equipment.

Lastly it is bad for the environment. But hey so is driving. Its alot like light cigs vs full flavor smokes. Either way your killing yourself. Besides I still ride my bicycle all the time. Plus I don't care.

/tldr: no, cat delete pipes aren't the worst thing ever depending where you live. I like mine. A magnaflow cat is on the to do list, amongst many other more pressing mods/repairs

 

[RedRyder]

Ha that's the same article I read when I was looking for one to buy. I wanted Random Tech but found such a good deal on the Magnaflow.

I noticed more responsiveness, and more sound. Not a huge difference though really.

 

[SykVSyx]

I know of one person running a test pipe up here in between e-tests.

Never heard any complaints.

I'm going to give a hi-flow cat a try and see if there is any difference.

 

[rdxd]

looks to be a very small gain in power - here in Aus. its illegal to delete the catback

 

[G'sAccord01]

I have a J32 with OBX headers, and 3" single exhaust with 1 resonator and 3"in 4"out magnaflow muffler. To me this s*** is loud and I really don't like it. I was wondering if adding a Cat or another resonator would help?