Cat or Test Pipe?

[GST_IceTea]

i just ordered my thermal R&D exhaust. my next step is to get the RRE downpipe. my situtation is whether to get the one with the cat or just a test pipe. i want it to be loud, but not to the point where ill get pulled over in 2 secs. if anyone could tell me how loud there car is with this similar setup thxs.

 

[Sik95TSI]

Get a test pipe

 

[DROPthatCLUTCH]

Well, I have stock exhaust, with a test pipe. And it`s pretty loud.
But screw it, it sounds good. It`s not an annoying loud at all.
Plus, who needs all the extra restiction from a cat.
CHOP IT MAN!

 

[josh408]

I'd say get a test pipe

 

[AK Maniak]

I might be wrong but if your gonna get pulled over for exhaust then it'll probably happen regardless of a test pipe or not.

 

[AMPPRC]

Test pipe

 

[spawn87]

i got a full 3inch turbo back thermal R&D exhaust with a hight flow 3inch cat and it sounds plenty loud deep on idle and people can hear me coming when im on the road.

if you run with out a cat (assuming your still stock t25) by 2600 it will sound too loud without a cat and you will get the attention.

i ran catless for a week on a 16g and it was not for me.

but first when you get your system get a test pipe welded with flanges so if you wAnt cat you can just bolt it on and take it off when ever you feel like.

FILL in your profile for future reference so we can help you alot easier and faster.

 

[agentorange313]

I have the RRE downpipe with an apexi n1 exhaust, had a test pipe, it was pretty loud

I put the cat(aftermarket highflow) in to pass inspection, I actually kept it in because it I like the sounds better. Its not as loud and less vibration. same amount of power. I never been pulled over because of my exhaust before, so i dont think it was very loud to begin with, I know the apexi has two resonators in it, but that might be because it is a fart can.

Overall I say get a high flow aftermarket cat and call it a day, it wont be loud and you know you can pass inspection, plus you are street legal (at least catback system)

 

[Absit]

The real question is do you have a visual inspection you have to pass (for the track or the state)?

 

[WizardTSi]

Why not just get a cat and have it legal? There are some pretty free flowing cats available and how annoying would it be to change out the test pipe. Even if it is just once in a blue moon it would get on my nerves. Just my two cents.

 

[99GSXblack]

I'm going to be going with a high flow cat on my setup. I doubt you'd notice much difference power wise.

 

[Zdrummer15]

Your exhaust won't be loud enough to get pulled over for it either way you go unless the cops around you are incredibly strict. Having a turbo in the way of the exhaust automatically keeps in quieter then if you put a similar exhaust on a n/a 4 cylinder car. I ran a downpipe that eliminated the cat for a year until I had to get it inspected and then installed a high flow cat to pass. It got a little quieter, but after awhile I didn't even notice the difference. If you only have visual inspection, you could run a test pipe with the shell of a cat welded around it and then never have to swap it. Just google "all-flow cat" if you're interested in one.

 

[GST_IceTea]

i live in MA, so i will need a cat to pass inspection. i think im gunna go with the RRE short downpipe with the cat.

 

[99ECLIPSEGSXDSM]

i bought both high flow cat cat and test pipe from RRE... test pipe sounds alittle lounder when you floor it but not that much louder when your just driving around or at idle. test pipe you get alittle more power to. i got both for the cat to pass inspection...

 

[TheWu]

I'm about to get a bolt on test pipe for my car, so I can switch to a CAT to pass emissions in case I move. However, does anyone know how to do a o2 Sensor bypass or where to fake a dummy o2 sensor? I have a 2.4 n/a.

 

[GMCometh]

I'm going with the exact same setup in a few weeks. Not only am I going with a cat due to MD state emissions...but it helps cut down on the stench of exhaust.

 

[spydergstftw]

i had the same concerns but said screw it and put a straight pipe on and i am never putting a cat on my car ever again! the exhaust sounds amazing and i havent been pulled over yet

 

[skatershawn]

I have a full 3'' turbo back with test pipe.. and it idles decently quite, its pretty mellow at a steady speed on the highway also, but when you stomp on it, it tends to get some what loud! But BELIEVE ME, its not bad, or anything like the rices! Its Very enjoyable!!

BUT if you have have to get you car smogged then you should go with the cat!!

 

[GST_IceTea]

im also ordering the evo III o2 housing. has anyone seen gains from this?

 

[Xeiros]

I just installed a Thermal R&D exhaust and a catless downpipe on my car last week. It's pretty mellow as far as I'm concerned. It will start to roar a bit if you get on it, but just cruising around I can't imagine anyone under the age of 60 thinking it's loud at all. Granted, my thermal exhaust is unmodified (it still has the 2 1/4" neckdown to fit the stock downpipe) so I'm sure that restriction has something to do with it sounding as mellow as it does.

 

[Zdrummer15]

I'm about to get a bolt on test pipe for my car, so I can switch to a CAT to pass emissions in case I move. However, does anyone know how to do a o2 Sensor bypass or where to fake a dummy o2 sensor? I have a 2.4 n/a.

Do a search on here because there is a way to rewire it so the ecu thinks the o2 sensor is still reading "clean" air. You can also try using a spark plug anti fouler on your exhaust. This allows you to mount the o2 sensor inside that which is then mounted on the bung in the exhaust. This keeps the o2 sensor out of the path of the exhaust gases so you may also avoid throwing a CEL by doing that.

 

[unplugme71]

I'd go with a high-flow cat and stay legal.

 

[crazyquik22023]

It depends, if you live in an area that has some kind of emission testing, like I do, I would get the short RRE downpipe. You can always get that on either way and just put the test pipe in when/if you want, and if it turns out to be too loud for you or you need to put a cat in for emission purposes you can do that.

 

[Hoot]

im also ordering the evo III o2 housing. has anyone seen gains from this?

Swapping out just one part and asking about gains in hp and torque is sort of odd. The idea for doing the Evo III O2 housing as well as the exhaust manifold, turbo (if you haven't gone to the 16G), dp, cat, and cat back is to avoid bottlenecks and thus boost creep. Do you see gains from just the O2 housing? Sure, if the rest of the system is ready for it... If you don't do the rest of the system then you have not removed all the bottlenecks in the out flowing gas and the addition of a "high flow" O2 housing is less meaningful.

For example, I still need to port my manifold and drop in a big 16G to complete my setup.

 

[eatsleepboostin]

Depends where you are living. I know in Sac, CA. we imports get pulled over left and right for being loud. BS. But if you don't mind the loudness, it's a big improvement without the cat. I run with cat and without cat and it's a big different in noise and horsepower wise. I would say if you can get a high flow cat, that's even better. A little restriction is good for torque.