I feel it’s important to point out that while a catalytic converter does reduce CO emissions, the main purpose of the design is actually to reduce smog emissions. Smog is a catch-all term for oxides of nitrogen (NOₓ) which are a medley of molecules formed during combustion which consist of a nitrogen atom bonded with various numbers of oxygen atoms, hence the ‘x’ in the name. The key to the cat’s function lies in bond energies of molecules, and the triple covalent bond in NOₓ molecules have much a much higher bond energy than the double bonds in CO, CO₂ O₂, N₂, and other common exhaust products. To remove the NOₓ molecules, the cat media reacts with the exhaust gas by becoming extremely hot, reaching temperatures comparable to the combustion chamber where the NOₓ was formed. Since it takes the same amount of energy to break the bonds as it does to form them, the NOₓ molecules disassociate into monoatomic nitrogen and oxygen as they pass through, and when they exit the cat the temperature drops below what would be required for NOₓ molecules to re-form. The result is a significant decrease in smog emissions and the presence of smog is the smell the emits from a cat-less setup.

This channel is quickly becoming my favorite. Love the channel man I've learned so much new wrx owner here. Its my first Subaru so i wanna do it right. Thanks for the great content!

Me who has n/a subaru: "Yes, boost creep, problem noted 👁👄👁"

I dont have a cat I have a dog, does that make me...catless

Its also important to note what hardware comes in the box with certain downpipes. Sometimes a cheaper downpipe will be missing a gasket or resuse bolts that were already on the car instead of new hardware.

Catted downpipe to keep it friendly with our neighbors😂

bought my 2012 in December and your videos have shown me that the original owner and his tuner did my car right. Thanks for all the great Subaru info

I've ran an Invidia catless j-pipe and a resonator delete on my 17' WRX for over year now because I really wanted that "diesel" spool sound. I've never had any boost creep oddly enough and have always been aware of the cons of running the set up. Then again this car has been through absolute hell and it's a miracle it's even running still lmao

All of your older videos are very entertaining brother. Have a great week.

"make sure you wash your hands and not touching people butts?" Love the content my dude!

Bro I love this channel so much. The way everything is explained is super clear and informative. I seriously hope your success comes because it is beyond deserved.

I smell my cats all the time. They're house cats, eating the same food, pooping in the same litter, and they smell completely different. It intrigues me. Nonsense aside, I learn something new in every one of your videos. You're becoming my favorite channel. I mean, I paused binging Breaking Bad to watch this. You're doing something right!

scrolling through sti vids for my sti and i see the TMG banner in the back. Much love brother!

I've had my WRX for a while now so I know most of the information. But it's always good for a refresher and new owners. Good job we appreciate the effort

Been looking for info on this topic everywhere. Dropped a sub. Keep it up!

Ewg with catless downpipe is a must. My wrx running strong with 178,xxx, learned a lot from your videos. Keep up the good work fellow Washingtonian.

The intro alone got me😂!! Very informative altogether 🙌🏽😎

Perfect video. Thanks! Just boosted my miata and noticed I was running lean at higher RPM's. I also noticed the boost was increasing from where I had it set. I installed a test pipe while installing the turbo system... but I'm thinking the cat is going back on. Thanks for explaining everything!

This guy don’t miss

I just got the Invidia catless downpipe and it's amazing. More flames, pops and noise. I had a Grimmspeed look-alike and I ran into a fitment issue because the internal wastegate was hitting a flange on the downpipe. EWG coming in the future...

We have a subaru WRX. This was very informative. We appreciate the breakdown. This cleared up alot of questions we had.

Video on when to consider getting a tune , pro tune / E tune etc. love the channel, I’m in the army right now I ETS in 2 months yuhhhhh

Sheeit dude i didnt know youre studying microbiology! My grandfather is a hugeee microbiologist here in the east coast. He a big part of laboratory alliance hes written books and all. Love your videos man

BOOST CREEP FIX!!! I used to own a 2003 WRX and then a 2004 STi. There is a fix we used to do on those for boost creep on a STOCK TURBO. We would enlarge toe orifice on the wastegate. I did several of them for other people too. When you have the downpipe off of the turbo you remove the clip and rod from the wastegate valve. Open the valve and grind a VERY SMALL amount off the wastegate hole and keep it round. You can always take off more, you can never put it back. if you take too much material off you won't get enough boost. Solved the creep issue on my STi with a catless downpipe and many others too.

Good info! I may add - If you want to run an OEM VFxx turbo on a catless downpipe, I recommend porting the internal wastegate (which is what I did on my car) It’s a simple process. Remove your turbo, take off the wastegate actuator, and remove the V-band clamp that attaches the exhaust housing. Use a mallet and remove the exhaust housing, being careful not to damage the turbine wheel. Take a Dremel and a grinding bit, and round off the corner that leads exhaust gas to the wastegate. DO NOT ENLARGE THE WASTEGATE HOLE, you’re simply smoothening the hard edge that leads to the wastegate. This encourages exhaust flow out the wastegate instead of going through the turbine. There are a few videos and forum posts on this process, so do your research. I’m on a VF48 e85 at 20 psi, never had an issue with creep. A 3-port EBCS might help, but there’s nothing that can truly eliminate creep other than having a larger wastegate Last and most important, GET A REAL TUNE 🤣

I know this comment is late but this is why I like my safety only county.... no emission. I'm catching up on all the old videos

Bro you are my new favorite channel.

Best wrx channel out there ,, been watch and subscribed at 771 and Anything I need to know I watch your videos keep it going

I don’t own a Subaru but still enjoy watching your channel. Good info and nice car

Yessss - I really wanted this topic. Thanks for doing this ❤️

Appreciate your channel. As a 2005 Subaru Legacy GT owner, its helped me understand ALOT. Kudos

I went Catless on my 2018 WRX. To minimize boost creep, I put on the Killer B EWGs and this thing is loud AF now.

I’m very glad I subbed to you, you definitely know what you’re talking about through all of your videos. I was told by my local tuning shop to get a catted J-pipe, is that a down pipe still? Is it basically just another way of saying downpipe?

Great video. Can't wait for the ewg video need one for my car as I have a grimmspeed limited catted downpipe but still having boost creep issues on my car

This is one of my favorite channels 👍🏽👍🏽👍🏽👍🏽👍🏽👍🏽👍🏽👍🏽👍🏽

Loving the videos man! I have owned a 2015 sti for 3 months now, went from a 99 GC8 NA to this and am so happy with it, your videos are very helpful for me and your great at explaining I can tell you know best!. Respect from Perth Western Australia 🇦🇺

2012 wrx tuned on 19psi.... intake top mount turbo back exhaust

Your vids makes me more excited about finally buying a wrx 😁

Love this video, I’m new to the subi community and I’ve learned so much, thank you!

3 years ago… stay safe from covid my friend… 3 years already is crazy

Great video and great explanation and comparison. I was very on the fence of what to go with and i have heard catted is the way to go but i wanted them “racecar vibes” but now i think i will go catted thanks alot!

i need ur motivation lmao good stuff as always

if you want to shoot flames, go catless

Love this guys’ videos keep it up man !!!

Yes yes please please do make a video on properly wrapping an exhaust 🙏

I know the car has changed since this video. But that thumbnail looks soooooo goooood! I wonder if a gt wing would suit my wrx. I track my car and would love to add some downforce.

I have always liked your videos good content!

Always killing it with the great content. Stay safe out there in Wa...craziness. Ouuuu T-shirt on its way. Will be rocking it out here at the east coast Subi meets when they finally happen

Great informational video. New subscriber. Going catted downpipe for my N55, will pair it with my charge pipe and BM3....hip hip hooray!

Keep up the good work, Love the videos. Wanted to see if you are considering installing aftermarket seats for the WRX/STI or the BRZ and of course making a video?

I didn’t know OTS maps don’t support catless downpipes, you saved my ass as I was JUST shopping for one👌🏻

What I learned.. always wrap your downpipe!! Got it

This was the best advice I've heard and I almost got catless downpis lol.cheers mate

i subscribed right when you gave the be safe warning hahaha love the energy

I’m planning to get a Tomei Expreme Ti single exit cat back for my 2020 wrx.

thoroughly well explained thanks!

Car mods is about finding balance. With car mods $ tip the scale heavily. Even with catted you can generate massive hp and torque and a sweet even loud exhaust note, if high decibels are your thing. Lastly you are emissions legal regardless of where you drive or end up driving should you move. One less thing to worry about.

Another great video! Keep it up!

Just discover this channel and really like it! Which video does he talk about pros/cons of voiding a warranty? Asking for a friend 😝

unrelated question, but what wheels are those? (awesome video by the way man!)

Great video again appreciate the info🤙

Bro, 100% video 👌👌. I bought a bottom range 09 wrx hatch. Nothing done to it. All I've done is 3" turbo back decat. STI style rear muffler been cut open and all the crap removed. Welder back up. Took housing off oem air filter front part to reviel filter. Half inch spacer last joint before rear muffler. Got the rumble, got the turbo spool sound, got natural pop and bang through gear change. No boost problem, and it's like a totally different car. It almost pulls my hands off the steering wheel through gear change. I'm in the UK running standard UK 99ron petrol???

Just left a microbiology research lab... Cool job, I'm a chemist. Environmental work is what I specialize in.

I would love to put one in my 21 Type s preferably catted

Getting a downpipe doesn't automatically void your warranty. Look up the Magnuson Moss warranty act. The dealership has to prove that your installed after market part is what caused said malfunction

I don't recommend starting up your engine in a closed garage whether its catted or non catted.

Brooooooooo garage door is almost closed on your front lip😂

How is the microbiology career like ? It sounds super interesting. Subie lookin real nice btw

It’s nice to find a channel based in Washington

Great video and great explanation! Thanks very much!

We need more pics of this wrb sti, looks awesome

I was looking at the turboxs catted j pipe since it’s on sale for a good price.

I'm confused now )) If I do not want to spend a lot for a catted one, will a catless just eventually fck up my Turbo ?

Hey man love the video. Also what kind of wheels are you rocking. Very dope. Thanks for your time.

Great video really informative

Tough choice, I live in Ohio, I don't think they mess with the emissions check. If i Go catless to match my Invidia R400, still need to get protune in order to run the intake as well. But with the situation of "THAT" the tuner is not working at the time. Good thing you clarified running catless won't work with OTS Maps.

When you buy a catless downpipe for your WRX when you had no idea what boost creep was and now want to question your existence and also question if you can throw 30 lbs of boost at your ej20

So I was told cause I started destroy my high flow and that I'm pro tuned and external wastegate and take out the kitty liter and I should be fine still just log afr so they can make sure everything still fine and apparently cobb discontinued downpipe and they don't make anything that you can't have in ca

I wish I would have watched this video sooner. I didn't properly wrap my downpipe like he said.. and now I have a lot of extra bills called children.

I went with a catted downpipe because I'm not a 20 year old Honda kid and I like my car to be comfortable.

My new subie guru! 🙌 Love the info.

what happens if i put a cx racing turbo manifold on a stock tune.

Just done my wheels on my evo x white but those wheels look nice what are they please? brill video pal

Really like your channel man, really chill vibes. Ill be sure not to grab anyones butts lol.

Yo Yo! Great vid as always! Recently pro-tuned my 06 WRX to stage2+ w/DC intake and STI intercooler BUT without adding a new catback exhaust for emission/noise reasons (I live in VA). Will putting an HKS Hi-power on a stock 06 downpipe work fine or should I do the catted downpipe as well? I'm hoping it'll fix the DAM problems I've had since we got it tuned. It wants to run faster but restricted by the exhaust airflow. Thanks in advance!

Why I ended up going with a catted over cattless for my wrx is because if you plan on running e85 in the future with a catted you can but if you have a cattless you are not able to

Just bought a "Turbo XS" chatted pipe for $550. Going to Cerakote the whole exhaust

I have an Invidia Q300 and the stock downpipe on my 2009 Impreza WRX currently. I’m a little nervous about emissions (I want to go Catted) and also sound laws in Massachusetts are WAY more strict

Regarding ceramic coating the down/j pipes: I'm assuming there's some specialized coatings for that specific purpose? Or does the plain old ceramic/graphene coating usually for the paint work the same? ✌

Hi I have a 2010 legacy gt I need help finding aftermarket parts I have a ej255 can’t seem to find parts any help will be appreciated first time with a trubo car thank you

Love my invidia catless jpipe and q300 exhaust. Downside is gassing yourself out at red lights or telling a passenger what that smell is

Hey man, I love your stuff and the information you provide. I am looking at getting into a 2015+ wrx. I plan to go stage 2. I am curious what your thoughts of buying a rebuilt title wrx. I plan to do mechanic check and everything that goes with that. Wanted to know your opinion on it though. Thanks!

What about running a Catless down pipe with NO turbo. I only have a muffler delete

smeedia huge fan!! currently collecting mods for my build watching your vids, have a blouch 2.5xtr 10cm with invidia catless down pipe would porting the iwg housing be sufficient enough to eliminate boost creep? or should i juat run a ewg? what causes boost creep when running a cattless downpipe?

how did you squeeze your car into taht garage

Might be stupid question. But if I go catless... And get headers with external waisgates, will that work as the waistgates for boost creep?

Nice work brother , I have a Sym's catted downpipe , I have run without it (cattless) and don't see much difference . I'm all in cause $3k I have to like it !

I might go catted downpipe only for the emissions reason. And also i don't care about sound so i want to sound as stock as i can. The only reason for me even thinking of a downpipe is because i am going to custom tune my car past my current tune and I've been told that i will need it since i will be running a lot of psi

I want to buy a cobb catted non resonated 3” j pipe/downpipe. Does replacing stock downpipe cause any reliability issues and or engine damage? A dealer said yes but everyone on the internet says no?

Will I have boost creep on a fully stock but decatted 2008 S-GT Hatch? The first cat is original but emptied the second cat is straight pipe with o2 sensor and spacer. (Its a ej20X japanese wrx)