Has anyone made their own cheap catted DP by buying catless and adding cheap cat?

[danbfree]

This, a buddy asked me to build his friend a cheap catted downpipe as a birthday present and enough people on the forums liked the idea that I eventually borrowed it back to build a weld fixture around and I sold them till my skill set developed enough to justify building my own proprietary design from scratch.

For what it’s worth that very first one is still on the road today, I did a pull with Jose on the way to work a few weeks ago (not fair, he hasn’t upgraded his turbo yet).
https://youtube.com/shorts/DsCx96HHvyg?feature=share


For $200 it’ll bolt right up and fit like a glove, which you can’t say for most sub-1k downpipes.

Thanks again for the insight! Yeah, you deserve the recognition as a purveyor of Rolexes of downpipes so I appreciate the straight honesty in your original reply I got via email , I don't even make $35/hr so "it is what it is" in what I'm looking for and that will certainly do the job on my Golf 1.8, not even GTI...

 

[FROSTYmk7.5]

48 state legal cats are only like $55, so is it possible to buy a cheap catless DP like THIS and have the cheap cat welded in above the O2 bung and be 48 state legal with a decent improvement in airflow?

Theory would be to fit an 11" total length cat between the V-band and 02 bung on a 2 piece DP like this. I'm sure the ends of the cat cut be cut down further to maybe 8" total length to help fit it? Or, as it says in the description, would have to add to the rear section, like on a CTS catted DP - with o2 spacer used on higher mounted bung and the cat below? I suppose that would be a cheap way to create your own CTS style catted DP, but they smell on startup until the cat further below heats up. If you can fit a 400 cell EPA cat above the O2 sensor, you wouldn't even need a spacer to pass smog/no CEL without any special tuning - I'm running a JB4 and plan to keep it that way for now. Of course, many people just run catless, but I imagine it would still be a massive improvement over the very restrictive 600 cell stock DP with sharp bends.

EDIT: Now considering THIS one that is not as cheap with a larger v band section and indeed just do it like a CTS catted and rely 100% on a the big fat L shape O2 spacer and cat after that. It will smell until it warms up, which will take longer since it's not as close to the turbo/engine to heat up faster.

View attachment 233660

I have this exact depo racing downpipe and I welded on a flow master 200 cell cat + post cat 02 bung on the rear section of the downpipe... I've had it installed since 2,000 miles (now at 21,000) with a j-style spacer and I've never had the CEL come on.(It does smell on cold starts but the smell doesn't ever genuinely bother me.) That being said, the fitment of the downpipe was a little off where it bolts to the subframe and it's certainly not 304 steel. If I could do it over I'd just order a MAperformance catted downpipe and call it a day.

 

[danbfree]

I have this exact depo racing downpipe and I welded on a flow master 200 cell cat + post cat 02 bung on the rear section of the downpipe... I've had it installed since 2,000 miles (now at 21,000) with a j-style spacer and I've never had the CEL come on.(It does smell on cold starts but the smell doesn't ever genuinely bother me.) That being said, the fitment of the downpipe was a little off where it bolts to the subframe and it's certainly not 304 steel. If I could do it over I'd just order a MAperformance catted downpipe and call it a day.

Thanks for the feedback. I don't expect everyone to read every post so I did order a MAP on eBay as a one-off deal from a random seller new for only $450 and I'm trying to get the seller to follow thru and actually ship it but that doesn't appear to be happening. So my original point of this thread was to look at some "outside the box" options that wouldn't set me back $700+ as a backup option, and after a lot of good feedback from kind folks like yourself taking the time to reply, I'm now looking at a legit deal for an ARM for around $400. I just have to wait until the 5th to see if the MAP is gonna ship, and if it doesn't, I get a refund and order the ARM catted DP. Again, thanks for helping reinforce my decision to go with an established complete setup!

 

[danbfree]

The eBay order for the MAP never shipped and once I hit the eligible date to cancel I got a prompt refund from eBay so I ended up ordering the ARM catted DP... Got it for ~$425 with coupon code COMEBACK that popped up from one of my plugins giving me 5% off the $447 sale price HERE. What's also nice about it is that while it comes with both a 3" straight thru and 65mm reducer, neither is already welded on so it should be easy to use the ECS 76 to 60mm reducer for my 1.8L stock exhaust. The cat is 200 cell so according to other threads and reviews it can either smell once in a while or really not at all but I will be using a L shape (J?) O2 spacer to avoid a CEL, should be a nice balance between added flow and not having much fumes/soot, it seems to sound great on GTI's so we'll see!

So there we go, found the best value in a well made, well fitting product that will also be easy to use with my 1.8L 60mm exhaust. Thanks again for everyone's feedback and advice!

 

[odessa.filez]

how has it turned out with CEL management?

 

[danbfree]

how has it turned out with CEL management?

I got my IS20 and DP installed a week and a half ago and zero CEL so far! It did have a bit of noticeable fumes at first, maybe the catalyst cells had to break in, but with the 200 cell count cat *before* the O2 sensor, along with a $10 generic eBay spacer, I don't see any issues with CEL's now or in the future and the fumes have gone down more since brand new. The DP itself is turning color from the heat and looks good too!

 

[odessa.filez]

I got my IS20 and DP installed a week and a half ago and zero CEL so far! It did have a bit of noticeable fumes at first, maybe the catalyst cells had to break in, but with the 200 cell count cat *before* the O2 sensor, along with a $10 generic eBay spacer, I don't see any issues with CEL's now or in the future and the fumes have gone down more since brand new. The DP itself is turning color from the heat and looks good too!

it's an attractive price point,.especially if CELs are manageable / rare.

did you notice any increase in lag going from is12 to is20?

 

[StorableComa]

For the ARM DP, You'd want a Vibrant straight spacer or like clone with a medium insert. At least, going through Jake's thread on spacers I came to that conclusion. Picked up a cheap 7 dollar clone and tossed it on my ARM DP after I got a CEL with no spacer. No CELs since and I've been running it about 8 months now. The reducer I found it easier to have the 3" custom pipe cut and APR's reducer welded in to fit the 1.8Ts smaller exhaust. That way I still get the V-band, and can use the OEM Pipe sleeve clamp for the connection to the stock catback.

Granted if a J spacer is working, good to know. Figured I'd post what me and others have had success with.
https://www.golfmk7.com/forums/index.php?threads/the-o2-spacer-thread.375034/

Looks like the seller isn't up on ebay for the one I bought, but here is an example. 35 is bit pricey though but it claims to be a real vibrant, I looked for something like this one as a clone for around 10 bucks though and haven't had issue.

https://www.speedlifemotorsport.com/performance-o2-sensor-spacer-for-cel-fix/

 

[danbfree]

it's an attractive price point,.especially if CELs are manageable / rare.

did you notice any increase in lag going from is12 to is20?

Not at all, the DP more than makes up for it, throttle response down/at low speeds is much improved having the DP.

 

[danbfree]

For the ARM DP, You'd want a Vibrant straight spacer or like clone with a medium insert. At least, going through Jake's thread on spacers I came to that conclusion. Picked up a cheap 7 dollar clone and tossed it on my ARM DP after I got a CEL with no spacer. No CELs since and I've been running it about 8 months now. The reducer I found it easier to have the 3" custom pipe cut and APR's reducer welded in to fit the 1.8Ts smaller exhaust. That way I still get the V-band, and can use the OEM Pipe sleeve clamp for the connection to the stock catback.

Granted if a J spacer is working, good to know. Figured I'd post what me and others have had success with.
https://www.golfmk7.com/forums/index.php?threads/the-o2-spacer-thread.375034/

Looks like the seller isn't up on ebay for the one I bought, but here is an example. 35 is bit pricey though but it claims to be a real vibrant, I looked for something like this one as a clone for around 10 bucks though and haven't had issue.

https://www.speedlifemotorsport.com/performance-o2-sensor-spacer-for-cel-fix/

So the one I am using is a full-on L shape, not J and is the same shape as Uro Tuning sells for $35 they say should work for the vast majority of applications, and mine is a $10 clone of that and works great... But, honestly it seems like *any* spacer should be fine with a catted DP that has the catalyst before the O2 spot... But good info to share overall, it may help others, especially those that are catless or have the 02 above the cat like with CTS catted.

Also, I kept the 3" v-band section and had the 76 to 65mm replaced by the 76 to 60 APR section so I can go full 3" later on. It cost me a full $100 to have the v-band transferred but was all I could find on short notice with my IS20 install already in progress, hehe.

 

[StorableComa]

So the one I am using is a full-on L shape, not J and is the same shape as Uro Tuning sells for $35 they say should work for the vast majority of applications, and mine is a $10 clone of that and works great... But, honestly it seems like *any* spacer should be fine with a catted DP that has the catalyst before the O2 spot... But good info to share overall, it may help others, especially those that are catless or have the 02 above the cat like with CTS catted.

Also, I kept the 3" v-band section and had the 76 to 65mm replaced by the 76 to 60 APR section so I can go full 3" later on.

Yeah, the 60mm pipes on the 1.8T threw me and was a headache for a bit. Police tend to ticket for loud exhaust, and I prefer the sleeper vibe so I cannibalized the 3" section for my reducer as I don't plan on upgrading unless I move states. The guy welding wasn't sure he could use the 76 to 65 section too, so figured better safe than another headache.

 

[danbfree]

Yeah, the 60mm pipes on the 1.8T threw me and was a headache for a bit. Police tend to ticket for loud exhaust, and I prefer the sleeper vibe so I cannibalized the 3" section for my reducer as I don't plan on upgrading unless I move states. The guy welding wasn't sure he could use the 76 to 65 section too, so figured better safe than another headache.

I'm enjoying the sleeper vibe for now too, just the DP adds just enough growl for some feedback while driving vs. *too* quiet fully stock... but huh, that's kind of weird he'd say that, it's the same v-band lip on both the 3" section and 76 to 65mm that are both included. I just made a decision on the spot, that I'd likely never just go with only a 5mm bigger exhaust so may as well have the v-band lip off that one transferred, so I only gave my install guy that section along with the DP to install. That's him in the pic (I added a bit later) showing off the results of the welder guy he found for me before he installed it.

 

[odessa.filez]

did ARM demand a signed waiver on the DP for who knows what the EPA is up to?

 

[StorableComa]

did ARM demand a signed waiver on the DP for who knows what the EPA is up to?

Nope. They don't even have the standard off-road/Track use only disclaimer on their page either. They do a lot of stuff with BMW, Audi and VW I think they've just been working with the past two generations. Liking mine so far, and FWD is easy enough to swap on ramps when I have to smog it for visual.

 

[danbfree]

did ARM demand a signed waiver on the DP for who knows what the EPA is up to?

Nope, not at all... And I'll be able to pass smog/DEQ here since it gets no CEL all without any tune blocks. Funny, because our cars new here are sold with CA emissions, but after 6 years they need to be smog checked every 2 years, but it is just a non-visual OBD plug in check that makes sure it is passing standard federal emissions/all readiness OK.