Catted or Catless

05Rex

05Rex

New member
I see a lot of debate on this subject and I am getting ready to upgrade my downpipe so here is the question.

Are you catted or catless and what are you thoughts?

My thoughts from what I have read are:

Catless -

obviously much much cheaper

+2 maybe 3hp over catted

a little louder...don't know if that is a - or +, leaning more towards - due to attracted attention from the fuzz and the possible PO'd neighbors.

People probably won't ride my @$$ as much due to the aweful smell...
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Civic Duty - if I get caught, and my luck I will, I get to donate more money to the, is it Federal or State government that I pay? Probably both

I was going to say bad for the environment, but I live in Rumford, I doubt anyone would notice...lol.

Boost Creep? Don't know if that is an issue or not but I read that without the backpressure created by the cat it can cause boost creep issues.

Catted -

Much more expensive

a little less HP

It is legal, just in case "The Man" wants a look see.

Allows people to get on my @$$ giving me an excuse to pass with my wife in the car
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The environment, I can hug trees guilt free, just before I cut them down to burn in my fire pit.

Well you can probably see which way I am leaning but I am open to influence and corruption, show me the strength of the Dark Side.

 
while i have no official experience with this, i vote catted. with cops being more aggressive about noise and (i forget where rumford is) cumby county has to pass emissions testing for a sticker. and quieter is always better, especially if the alternative is being loud with only a slight power gain

 
Rumford is in Oxford County, no sniffer test yet but who knows what our political leaders may have in mind for the future. Gotta keep our liberal Mass neighbors happy so they keep bringing there money north right.

 
^wow i should have known that. I'd be careful with the new "amendments" to the exhaust laws making it sound like cops have more creative license to determine what's too loud. but mine's pretty quiet so i don't have to worry:D

 
And the environment. I don't buy the whole global warming thing, but the amount of pollutants that get out of uncatted systems is crazy. I'm talking about solids, not the "greenhouse gas" BS. solids are what the cat catches AFAIK, other than mice.

Running a lawn mower or similar non-road engine (that meets phase-2 federal restrictions) for an hour pollutes (solids, not gases) as much as driving a car (that meets federal restrictions) for over 500 miles. I forget the actual number, but its closer to 600 and may actually be over 600.

Imagine those numbers without a cat on the car.

 
How about a high flow cat? Doesn't take away much hp and keeps the police happy.
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I was actually leaning more toward that. I am debating on:

1. if I should pick up an aftermarket high flow cat and have it welded in either somewhere after the bend so it is more visible when being inspected or right after the where it attach's to the turbo. I heard it gets hot faster and starts burning it off quicker when it is up above the bend and that is why the catted downpipes are set up the way they are. Not sure if there are any other benefits so chime in if you know of some.

2. If I should pay the extra and get a catted downpipe, it seems to be at least $100 and up, more expensive depending on the pipe you get but am I really getting anything more for my money? A high-flow cat is a high-flow cat and a downpipe is a downpipe as long as it is bellmouth and 3" right?

And the environment. I don't buy the whole global warming thing, but the amount of pollutants that get out of uncatted systems is crazy. I'm talking about solids, not the "greenhouse gas" BS. solids are what the cat catches AFAIK, other than mice.
Running a lawn mower or similar non-road engine (that meets phase-2 federal restrictions) for an hour pollutes (solids, not gases) as much as driving a car (that meets federal restrictions) for over 500 miles. I forget the actual number, but its closer to 600 and may actually be over 600.

Imagine those numbers without a cat on the car.
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Yeah, that is what I was thinking, there is just no reason to pollute that much more for maybe 2-3hp gain from what I have read.

So that is 3, not counting myself, for catted. No one is going to chime in and say how catless ftw, or even play devils advocate just for arguments sake

 
That make 4 for catted.

Is there a good or bad high flow cat out there? I have been looking at some ebay cats that range from $50-$70 shipped or there are Magnaflow for over a $100.

Anyone know if it matters if that cat is before the bend or after?

 
You want to just buy an aftermarket downpipe that already has a cat.

I've been using the ERZ high flow catted DP for a year now and it's been great. The best part about it was the price... at $299 shipped, couldn't beat it for a catted DP.

 
I have been trolling forums looking for a good deal, found a few ok deals out there just nothing that has grabbed my attention yet. Nothing that needs to be done overnight, I am still enjoying my newly installed Grimmspeed uppipe! I usually spend a couple of months researching things before I finally commit to something anyways.

 
You want to just buy an aftermarket downpipe that already has a cat.
I've been using the ERZ high flow catted DP for a year now and it's been great. The best part about it was the price... at $299 shipped, couldn't beat it for a catted DP.
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same here and for an 09 wrx, and if you're worried about throwing codes, i have an 02 bung to bring the sensor out of the stream so it wont turn on. although i could disable the code with my tuning software....

 
Better yet just weld a fake cat on haha

I'm catless, but for no more of a reason than that's what i have always done...

 
I have a friend who runs cat-less *wink*

2.0 03 wrx reaches 18psi of full boost at 2800 rpm and is really moving by 3200 rpm. Running bellmouth mad-dad for superior flow.

I have read that when ppl go from cat-less to a cat they can notice a difference. But i've never done that and don't know how much the difference is.

Boost creep, i believe, was an issue for the 2.5 STi of some year. Either way it can be tuned out, as well as cels and a lot of the smell (which i kinda like). Should def get a tune with whatever DP you go with. That's where all the fun comes from!

Nearly all of your sound comes from the cat-back. You might get a different note slightly without a cat.

But high-flow cats probably work awesome and make life simpler should your exhaust come into question.

 
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Better yet just weld a fake cat on haha
I'm catless, but for no more of a reason than that's what i have always done...
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Well if I went catless that is what I was going to do. Found one online for like $50, looks just like a highflow cat.

I have a friend who runs cat-less *wink*
2.0 03 wrx reaches 18psi of full boost at 2800 rpm and is really moving by 3200 rpm. Running bellmouth mad-dad for superior flow.

I have read that when ppl go from cat-less to a cat they can notice a difference. But i've never done that and don't know how much the difference is.

Boost creep, i believe, was an issue for the 2.5 STi of some year. Either way it can be tuned out, as well as cels and a lot of the smell (which i kinda like). Should def get a tune with whatever DP you go with. That's where all the fun comes from!

Nearly all of your sound comes from the cat-back. You might get a different note slightly without a cat.

But high-flow cats probably work awesome and make life simpler should your exhaust come into question.
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Well I wasn't sure about the boost creap, I just saw a lot of posts when doing searches and trolling forums. I have an AP so I plan on going stage 2 as soon as I get the downpipe. I have read both sides, I think I even read somewhere with the right tune you don't need a cat to pass emissions cause the fuel/air ratio is so well managed by the ECU, I don't know about that, but I am sure a good tune will spit a lot less fuel out the back end. As I said though, I am using the default 91 octane stage 2 off my AP so I don't how good of a tune that is going to give me, probably pretty generic.

I want to go catted but at the same time catless is so much cheaper. I could could be out the door with a fake cat welded into a Godspeed DP for about $250, when just a catted pipe alone will cost me $300+ depending on what I get. Like I said, I can also go with the in between and get a catless pipe, a generic 3" highflow cat have it welded in around where the midpipe should be so it is visable and still be in under $300 for the whole package maybe just over $300 if I get a name brand cat like Magnaflow or something. I just want to make sure I am not going to take a significant hit in performance going that way.

 
An option along those lines is using a "shorty" DP. It's esensially just the down part of the pipe. Then i'm sure you can find/build a high-flow cat to go between the shorty and a cat-back (or re-use your stock one, i think). With that you can also put a straight pipe in there instead of the cat and see for yourself what the differences are. I may go that way if a few years.

 
An option along those lines is using a "shorty" DP. It's esensially just the down part of the pipe. Then i'm sure you can find/build a high-flow cat to go between the shorty and a cat-back (or re-use your stock one, i think). With that you can also put a straight pipe in there instead of the cat and see for yourself what the differences are. I may go that way if a few years.
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i have the maddad shorty DP for my 08 and its great! good sound and power. i used the stock cat but punched it out so im catless except the up. but looks stock=)

 
i have the maddad shorty DP for my 08 and its great! good sound and power. i used the stock cat but punched it out so im catless except the up. but looks stock=)
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But wouldn't you loose a good amount of performance staying with the stock mid-pipe due to the fact it is not 3"? I thought part of the whole point of upgrading the down pipe to make a Turbo-back was to go 3" all the way to increase flow?

 
No. You would be surprised about how much you don't really need a full 3" exhaust. The guys over at Rallitek run a 08 WRX with an AVO 380 turbo, making buko power.... and all through a STOCK CAT BACK.

 
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