# Effects of catless testpipe on this motor?



## brettley (Oct 7, 2011)

Hello all,

As you may be aware of, I come from the turbo world, where freeflowing exhaust is everything after the turbo, but I am not as familiar with NA motors. I am under the impression that removing even a healthy cat (im just shy of 50k miles on the car), I will gain both horsepower AND fuel economy. I saw this effect on my turbo B6 passat, but have not tried this on an N/A motor, as the last one I had was a subaru, and they claimed to have power losses with cat deletes. 

Are any of you running the USP Catless Test Pipe? I was thinking of picking it up here this week and bolting it up, but want to hear from any first hand experience on the topic. Any cheaper/better ones out there? 

TLDR: If you are catless, how has it effected your power and your fuel economy?

Thanks as always guys!


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## ojams (Feb 19, 2015)

I'm getting one installed this weekend hopefully, will let you know


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## brettley (Oct 7, 2011)

ojams said:


> I'm getting one installed this weekend hopefully, will let you know


Awesome! I may order mine Friday.. or wait until Monday so I can hear your impressions . What has been your deciding factor in the purchase?


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## ojams (Feb 19, 2015)

I was on the verge of buying it but since with shipping it cost nearly 350 and i could get a whole catback for just a little more i was torn, what pushed me to get it was when they had the spring sale, i got mine for $200. I heard that it sounds really good and gives a noticable (but small) boost in power and especially since i have the apr cai on mine its gonna sound fantastic hopefully


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## brettley (Oct 7, 2011)

ojams said:


> I was on the verge of buying it but since with shipping it cost nearly 350 and i could get a whole catback for just a little more i was torn, what pushed me to get it was when they had the spring sale, i got mine for $200. I heard that it sounds really good and gives a noticable (but small) boost in power and especially since i have the apr cai on mine its gonna sound fantastic hopefully


I wish I could have gone with the APR CAI, but alas I have the Passat, and did not want to be my own test dummy as to the fitment on the seemingly wider car. I have been reading the increase in power too, hopefully you have good things to say about it and I can get my daily a nice extra boost in powa! I have the aFe intake on my B7 Passat and it sounds awesome!


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## ojams (Feb 19, 2015)

I love the sound of my cai haha it's great and ok stay posted for updates soon


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## tay272 (Aug 22, 2007)

This was literaly the 1st mod I did on my car besides fashioning my own intake. Definitely gives a deeper and more burbly growl to the exhaust note, especially on deceleration. Add an exhaust to the mix and you get some seriously good exhaust notes outta the 2.5. It will bump the power in the mid to high range abit but may take some low end power. I felt the difference after install on the buttdyno for sure. Helps the engine exhale better at higher rpms by getting rid of the biggest restriction in the stock system. Mpgs will most likely not improve though


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## mjb8482 (Mar 4, 2008)

Might not of heard of it but the tsudo downpipe is a great deal. Cheapest I found . Full polished 304 stainless, 3 bungs and fit perfectly. Working great for me so far. Definitely no improvement on the mpgs though. Too hard to stay off the gas.  love the sound!


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## brettley (Oct 7, 2011)

mjb8482 said:


> Might not of heard of it but the tsudo downpipe is a great deal. Cheapest I found . Full polished 304 stainless, 3 bungs and fit perfectly. Working great for me so far. Definitely no improvement on the mpgs though. Too hard to stay off the gas.  love the sound!
> 
> 
> Sent from my iPhone using Tapatalk


Lucky for me I have 2 other cars to rip around in, but I do know I will use a bit heavier foot. My planned exhaust (usp testpipe no cat or res, 2.5" cat back with mandrel bends and 2 magnaflow 14x4x9 mufflers with a nice tip on the end. Unfortunately I have yet to find ANY pre-assembled kit for the Passat so it will be ALL custom fab work for the cat back.

After hearing tay272's review of his testpipe, I went ahead and ordered mine from USP, and by the time I read about Tsudo this morning, it's too late =( Good find and does look like very good quality!


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## mjb8482 (Mar 4, 2008)

Good luck with the build! Post some sound clips when you are done. Passat will sound badass with that setup. 🏻🏻


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## tay272 (Aug 22, 2007)

Just gonna forwarn you, taking out the resonator might make the exhaust note very raspy. Since your putting in two mufflers though, that could counteract that. Just what Ive heard from alot of people with the 2.5 that have done it. Could always throw one in the mix if the sound doesnt end up too pleasing.


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## DerekH (Sep 4, 2010)

You'll want a resonator, any 2.5 exhaust i have heard without one is pretty ricey.


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## brettley (Oct 7, 2011)

good to know that if it gets raspy thats what I can expect! Wonders of custom fabbed exhaust is I can change it up as much as I want  this thing will never be a 500hp monster like my other car, but I want it to sound amazing every time I give it gas!

Still debating on a burnt tip muffler tip though... not a fart can, but just the tip (just to see how it feels)


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## ojams (Feb 19, 2015)

Sorry for not updating yesterday been busy but I did get it installed and I've been driving it around the sound in the cabin is barely any different and when you are driving lightly you can't tell you have it on but holy hell does it sound good from outside


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## brettley (Oct 7, 2011)

ojams said:


> Sorry for not updating yesterday been busy but I did get it installed and I've been driving it around the sound in the cabin is barely any different and when you are driving lightly you can't tell you have it on but holy hell does it sound good from outside


Are you on any kind of cat-back system or is it stock otherwise? Did you notice an increase in power or change in how it drives? Whats the weight difference?

Mine comes today and I am getting SUPER excited!


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## ojams (Feb 19, 2015)

only other mod is a cai, it is slightly faster but nothing too crazy, it makes really nice sounds tho


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## brettley (Oct 7, 2011)

ojams said:


> only other mod is a cai, it is slightly faster but nothing too crazy, it makes really nice sounds tho


Did you install it yourself? If so, how hard was it to loose the nuts on the header? Did you need pb-blaster and/or new studs? Im at 50k miles and the bolts look pretty healthy yet so I hope it comes out painlessly.


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## ojams (Feb 19, 2015)

brettley said:


> Did you install it yourself? If so, how hard was it to loose the nuts on the header? Did you need pb-blaster and/or new studs? Im at 50k miles and the bolts look pretty healthy yet so I hope it comes out painlessly.


I gave a local shop 100 bucks and let them do it, i have 67k miles and they had to burn the bolts off


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## ojams (Feb 19, 2015)

UPDATE. I got a cel, i drove it around all day yesterday with no issues and this morning i got a stupid cel. ive contacted usp for some help and im gonna see what vagcom says as well after work today hopefully its just letting me know im missing the cat and its not running lean or something


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## brettley (Oct 7, 2011)

ojams said:


> UPDATE. I got a cel, i drove it around all day yesterday with no issues and this morning i got a stupid cel. ive contacted usp for some help and im gonna see what vagcom says as well after work today hopefully its just letting me know im missing the cat and its not running lean or something


So, a common misconception is that the second o2 sensor (the one after the cat) will cause you to run lean if you have no cat. The second sensor is purely there for emissions, so its easy to fail inspection if you have a gutted cat or no cat. The second sensor won't affect your AFR at all. The first o2 sensor affects your AFR and your engine parameters. If the upstream o2 is bad then youll have problems, but if its just because of the cat delete, youre fine =) I would recommend getting the Torque app, and keeping a little bluetooth dongle in your car that plugs into the OBD2 port, its handy for running quick codes and making sure everything is ok, that way you wont need to keep a laptop charged and in your car =)


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## mjb8482 (Mar 4, 2008)

Did you use a spacer for the 2nd O2 sensor? That should make the CEL go away. Mine came with a 90 degree spacer and I have been CEL free since day 1.

The post-cat sensor detects the "health" of your cat. Since it is no longer there, it is throwing a CEL thinking it is shot. The spacer pulls it further away from the exhaust stream, fooling it into thinking all is well.

Also--depending on where you live, (Like CA or NY) you may have 3 O2 sensors, like I do.


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## ojams (Feb 19, 2015)

Glad to know it's not running lean, also I've got a bt dongle in the mail as we speak  and as for the spacer mine came with the 90° thing too and was running fine the first day, and now I've got an annoying light on my dash, I'm not gonna blow 600 on a tune like usp recommends anytime soon. although now that you mention it my car did originally come from New York According to the vin is there any way to check for the 3rd sensor and if it's there delete it?


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## mjb8482 (Mar 4, 2008)

Correction: the NY and CA cars have 4 sensors. I don't know of a way to delete them, but the first one is in the exhaust manifold, second is in the front of the cat, the third is right after the cat and the fourth is downstream of the Cat. I wouldn't bother trying to delete. Not sure how you would. 

Definitely no need to spend $600 to eliminate the CEL. The spacers that come with the test pipes don't always work for everyone. Here's a link that might just help out. If this doesn't solve it, something else must be wrong...
http://roc-euro.com/oxygen-sensor-spacer.html?___store=smarttheme_en


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## brettley (Oct 7, 2011)

mjb8482 said:


> Correction: the NY and CA cars have 4 sensors. I don't know of a way to delete them, but the first one is in the exhaust manifold, second is in the front of the cat, the third is right after the cat and the fourth is downstream of the Cat. I wouldn't bother trying to delete. Not sure how you would.
> 
> Definitely no need to spend $600 to eliminate the CEL. The spacers that come with the test pipes don't always work for everyone. Here's a link that might just help out. If this doesn't solve it, something else must be wrong...
> http://roc-euro.com/oxygen-sensor-spacer.html?___store=smarttheme_en
> ...


WOH! THAT THING LOOKS AMAZING AND LIKE A GOD SEND!!!

United Motorsports offers a tune for $400 that is upgradable after you get an intake manifold too, they are a great company and my big turbo B6 Passat runs their software flawlessly. I am not sure if they support the MAF-less engine though, haven't looked into that very much yet, my big incentive will be remove the 110 mph top speed restriction my ECU has on it.

I'll look into it when the car is good at 110 lol.


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## ojams (Feb 19, 2015)

http://www.uspmotorsports.com/Exhau...e=inbound&utm_medium=email&utm_campaign=brian this is what usp recommended will this work, might as well get this if it works and its half the price


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## tay272 (Aug 22, 2007)

110!? Theres no way thats your stock limiter. Should go all the way to 130 or slightly above stock unless the Passats were tuned very differently. As far as I know though, the standard limiter for most modern VWs is like 130 except for the sportier models like the GTI and other stuff. Then 155.


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## mjb8482 (Mar 4, 2008)

I'm thinking next year I will get the UM turbo+SRI tune. Not thrilled with my C2 tune. Or maybe IE if they come out with one...


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## brettley (Oct 7, 2011)

Yea! I have a 5spd manual in my b7 Passat, and while still in 4th gear I can hit 110, and then all power drops and I can't get over 110. Even shifting to 5th only nets me at most 113mph... All of this testing was done in Mexico of course


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## ojams (Feb 19, 2015)

update I just got a new code p2275 its running rich ****ing pos down pipe waste of money


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## mjb8482 (Mar 4, 2008)

I have read that sometimes a spacer is also needed on the sensor upstream of the cat. Might be something to try. 


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## ojams (Feb 19, 2015)

so I need 2 spacers?


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## mjb8482 (Mar 4, 2008)

Sounds like it. I was reading up in the 1.8t forum and the 50 state emissions cars seem much more sensitive. The solution to the code you are having was to have a spacer after the cat and right before it. I wouldn't give up yet!


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## ojams (Feb 19, 2015)

but wouldn't the first o2 sensor affect a/f ratios even more if the readings where off because of a spacer? I wonder if a good tune can fix it


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## mjb8482 (Mar 4, 2008)

The last 2 sensors only monitor the health of the cat. The first one controls AFR. 


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## DerekH (Sep 4, 2010)

ojams said:


> but wouldn't the first o2 sensor affect a/f ratios even more if the readings where off because of a spacer? I wonder if a good tune can fix it


A tune will fix it, im running the EJ header with high flow cat and my UM tune got rid of the cel.


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## ojams (Feb 19, 2015)

mjb8482 said:


> The last 2 sensors only monitor the health of the cat. The first one controls AFR.
> 
> 
> Sent from my iPhone using Tapatalk


mine only has 2 sensors


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## ojams (Feb 19, 2015)

DerekH said:


> A tune will fix it, im running the EJ header with high flow cat and my UM tune got rid of the cel.


what headers do you have? is there a link to the site. did it improve performance at all?


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## DerekH (Sep 4, 2010)

ojams said:


> what headers do you have? is there a link to the site. did it improve performance at all?


I have the eurojet header. they arent made any more. it didnt do much when i got it. it was one of my first mods, i would imagine it does more now with the sri and a proper tune.


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## MiffedRatx1 (Aug 10, 2009)

I've got a tsuedo downpipe, no issues at all. Installed with the o2 spacer and no CEL either. Matched it up with a used Eurojet exhaust system and sounds great. Only thing bad about it is I've got a bad resonance in the car at about 2200-2300 rpm. Above or below that threshold, it's pretty quite until I get in it. 

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## mjb8482 (Mar 4, 2008)

I also have the tsudo. Best deal out there imo. Same results as you. Love it. 


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## theroccoman (May 8, 2007)

Where are you guys finding the Tsudo? Is that and ebay special? I ask because i'm looking for one for my JSW to compliment the AWE exhaust on it.


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## mjb8482 (Mar 4, 2008)

http://www.semotors.com/tsudo-vw-rabbit-golf-06-10-2-5l-mk5-2dr-4dr-hatchback-downpipe/

Works perfectly on my Jetta. Not sure if it will fit the wagon but I don't see why not. The quality is top-notch. It is exactly as shown in the picture. Can't beat the price. It looks like a cat but it's fake. Also helps cut some of the harshness. 


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## mk6matt (Jan 26, 2013)

http://www.amazon.com/Tsudo-Rabbit-...&qid=1439517785&sr=8-1&keywords=tsudo+2.5l+vw 

Thats where I got mine. Fitment wasn't perfect but the price was right.


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## theroccoman (May 8, 2007)

mjb8482 said:


> http://www.semotors.com/tsudo-vw-rabbit-golf-06-10-2-5l-mk5-2dr-4dr-hatchback-downpipe/
> 
> Works perfectly on my Jetta. Not sure if it will fit the wagon but I don't see why not. The quality is top-notch. It is exactly as shown in the picture. Can't beat the price. It looks like a cat but it's fake. Also helps cut some of the harshness.
> 
> ...



Well for a buck fifty and free shipping that's a done deal, IF i can figure out if it'll fit on my wagon. 

It seems like USP Motorsports is one of a few if not the only other place that sells downpipes and they have the golf/rabbit/jetta/sportwagen all using the same part so i think i'm good to go.


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## mjb8482 (Mar 4, 2008)

I would think so too. 🏻


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## TheMKVader (Jun 16, 2015)

Bringing this back from the dead, tried to order this pipe but i guess they are not in stock. Anyone know who has them in stock?


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## theroccoman (May 8, 2007)

TheMKVader said:


> Bringing this back from the dead, tried to order this pipe but i guess they are not in stock. Anyone know who has them in stock?


I ordered my Tsudo from semotors.com and they're still showing them as "In stock" 
http://www.semotors.com/tsudo-vw-rabbit-golf-06-10-2-5l-mk5-2dr-4dr-hatchback-downpipe/
Took only a few days to get to me, now i'm hoping to get it installed this weekend.


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## theroccoman (May 8, 2007)

I just wanted to send out an update on the Tsudo downpipe i got. It needed a little grinding to fit my 2.5 wagon but it's on, and it's LOUD! I have it paired with an AWE touring cat-back and it has some serious sound to it. It has a lot of growl and the butt dyno says it free'd up a few ponies but i'm not sure it's worth it for the volume.


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