Cat removal with stock exhaust?
 

I do not have the money for a full cat-back exhaust system but really would like to get some extra sound. Anyone know how replacing the oem cat's with straight pipes, lets say from fast intentions, and keeping everything else stock would sound? Can't find the specific setup on youtube. I don't want very loud, I want it to be noticeable though. I can't throw a CEL either for emissions purposes. Oh, I do not want a lot of rasp either, some is ok though. Any help is greatly appreciated!:tup:

It will be raspy bc you're using the stock exhaust but it will sound a lot better. You will also get decent gains. I think I posted a vid up here somewhere with the setup you're looking for.

Then you're most likely going to have to get the car tuned after you take the cats off.

Yup, with test pipes, the o2 extenders MIGHT work for you but you'll probably have to get them tuned out. Some states can actually see when the ECU has been modified and will automatically fail you. Unsure of Illinois emissions and equipment and if they put you on the sniffer, you will fail while hes walking up to put the thing in the exhaust lol.

I would look at the member FS threads for deals on exhaust components. People here change their exhausts like they do underwear. There is a midpipe back 5Zigen exhaust for $400 floating around, some short tails, and other inexpensive options for quality parts. You will get the extra volume you want, spent little money and get no CEL.

I would suggest going with some ART pipes and AAM short tails. Can probably get both used for ~$400

You can get cats for cheap and if they are engineered right you won't throw a cel. I ran GTM unreasonated test pipes, no tune but the sensors are set where no CEL came on.

I had this set up and it is extremely loud. If you just want sound, go with just the AAM short tails. If you want sound and performance get a aftermarket exhaust. I got an AAM 2.5" True Dual and I love it with my Art pipes.

Here is a link to my thread. There are many others! http://www.the370z.com/intake-exhaus...AM+short+tails

Thanks for all the feedback guys, I think I'm going to save a little longer and go with the FI catback with 12 inch resonators. I was going to get their HFC's as well, but decided the extra $500 is a little too much for me at the moment.

In the last vid your car sounds outrageous :driving:

It was pretty wild...I really liked it but for a DD it got way too much attention and I want to keep what I have left of my hearing. LOL

OP, you have similar concerns to me. Wanted a better sounding exhaust without breaking the bank, maintain all emission standards and not take a chance on voiding any warranties. Please keep in mind, I do not plan on doing any additional mods to my car, this is it, as far as the engine is concerned. Good info from jcosta on this link below.

http://www.the370z.com/intake-exhaus...hing-mods.html

Was initially planning on going w/Fast Intentions, cost w/shipping to HI is over $1,600, plus the local performance shop I would use for installation charge is $150. The owner of this shop would put on any exhasut I ordered for $150 but gave me two other options. Either one of these would cost only $400. Replace stock muffler w/two seperate mufflers from the last flange (this would cause 2 bends by the mufflers) or cut the existing pipes before the last flange and weld larger 2.5" pipes which attach to mufflers for a very straight exhaust flow. I chose option two, pic attached.

Very happy with my choice as this did not add any weight to my car, sound is much better than stock, original exhaust tips were kept, my butt dyno feels like their has been some increase in power, plus a savings of over $1,350. Might be an option for you.

OP don't overlook the fact that the stock cats rob some serious HP. I made ~293WHP on a dynojet after installing test pipes.

The resonated test pipe from FI is also a option, since it's relatively cheaper than their HFC's, but I wonder how much louder it will be then with the HFC's? I'll be getting the 18 inch resonators from them if I decide to go with either setup in order to keep the sound level livable. Will the tone be different between the two?

you might get a little less rasp with the hfc's but considering you're getting 18in. resonators it shouldn't be "unlivable" however if Chitown is hard on emission testing then get the HFC's

Basically as long as theres no cel i should pass emissions, no sniffer testing.

Sent from my SCH-I535 using Tapatalk 2

I've decided on the FI system with 18 inch resonated cat-back, but im deciding either between their resonated test pipes or high flow cats. the plus about the resonated test pipes is more power and cheaper. the negatives is the smell of gas (might be a positive since i love the smell of gas!) and black soot build-up on the rear lower bumper. anyone have either setup and can help me decide?

Never have had soot build up on my bumper... lol

Inside the tips, oh hell yes. Never on the bumper though.

I mean, the gas fumes do get old if you like to warm the car up in the garage (with the door open) as the gasoline still finds its way back in. And instantly permeates whatever you're wearing, making you a walking gasoline air freshener.

I don't really care in my situation, because racecar, but you might care if you daily drive it.

Wow the gas smell is that bad? I know my Ducati and previous gixxer motorcycle would always make me smell like gas, but a lot of that has to do with being out in the open on a bike. I'd think with a car it would isolate you from the smell more since it's more enclosed. Is it bad enough to the point where I'll walk into work and right away people will smell gasoline on me?

If you start up and drive immediately, you'll be fine.

If you start up and let it idle for a while inside a garage, you're gonna pick up some of the smell almost unavoidably unless you have an activated carbon cabin air filter lol

With mine, if I start it and then don't immediately leave, I'll smell like it within 1-2 minutes. Sitting inside isn't as bad of course, but if you have the defroster on or external air at all, you're gonna pull some of it in.

Well to remove the stock cats..one it's a federal offense...just saying on that one but I doubt they will come after anyone for that one. Also it will throw engine codes for both banks unless you get them tuned out. I know, I more or less had straight pipes on my old Z. Driving it was a beating due to the noise but the turbo made up for it. You will have power gains somewhere around 30+hp gains.

With the F.I TP's you will NOT through a code due to the extended 02 bungs.

I had the Berk test pipes on mine and it threw the same codes all the time. Just went into Cipher and shut them off.

It's illegal to remove a working cat. Poke a few holes in the OEM cats after you get them off and claim you hit some road debris.

Well that's the Berk, if I'm not mistaken those are more likely to throw codes, especially since they don't have the extended o2 bungs.
Lol, I'm really not worried of authorities raiding the shop while my cars getting the pipes installed just to make sure they aren't removing a working cat.

I've never heard of anyone having an issue with the feds about removing a cat. Technically, though, it is illegal. If they ever decide to enforce it 99.995% of this forum is getting popped, myself included.

I burnt mine up...so spending $1300 on a new set or $200 for some test pipes. Easy choice...plus the hp gain:tup:

dude i really hope u didn't spend 1300 on a set of cats, otherwise u got ripped lol

anyone know the differences of the Berk resonated test pipe from the Fast Intentions one? Will the Berk through a CEL, will it sound any different?

Berk is 200 cell, Fast Intentions uses 300 cell I believe. Could be incorrect if someone wants to verify.

If I were talking about the high flow cats you would be correct, but since I'm talking about resonated test pipes there are no cells associated with either

SRY, read quickly. Oh well,

Hell no...I paid $150 and he was surprised I was willing to pay that much. Dealer wouldn't take it back with test pipes :tup: