sti emission test
 

what are the experiences here passing emissions test with an sti with modded exhaust. i.e.-catless downpipe and such. It looks like 96 and newer vehicles just get the obdII test so does that make it easier or harder to pass?

It's cake to pass as long as you have no CEL's and the ECU hasn't been reset in the last week or hundred miles (roughly).

Go to Fred's.

I'm asking becuase I am looking at an sti with a catless downpipe, and sti are catless upipes, so unless I am mistaken that only leaves a small one in the midpipe. So if I have the cobb set to stage 1 with no CEL codes showing I should be able to pass? I would hate to buy the car with the modded exhaust and not be able to pass it. :(

With a catless DP, you should run stage 2, and yes, as long as there is no CEL and the ECU is not "not ready" due to being reset recently, you'll pass. They don't do a sniffer test so you could be catless and still pass.

wow that's wonderfull news...thank you for the quick reply

it has a coated catless downpipe and borla hush on it currently. If I get this car and it doesn't pass I may have to kill you. :lol:

:eek: :P

Well, all I can tell you is that I have that exact setup (borla hush, coated catless DP as well as a catless coated UP) and I've passed every time (3 years now).

I guess the only thing that would suck is if the car had CEL's but somebody pulled the physical CEL to hide them or something. I'd get it checked out just in case. AutoZone can check for any CEL's for free or you may want to pay a mechanic to check it out for you and have them pull any codes...

wow, same setup... I know this is relative but how does it sound compared to stock. I imagine the dp adds a bit of growl.

Well, it comes with an AP and no codes so I imagine I can pass just like you.

The 2.5L might add some growl as compared to my 2.0L but it's surprisingly quiet...definitely louder than stock, but hardly audible on the freeway (Re: no drone). It's one of the quietest catbacks I've ever heard, but it's a true 3" all the way through. :cool:

It sounds perfect at sea level, but at this elevation, it's a bit on the quiet side.

looks like I am picking up an sti but it's all stock exhaust so I have some deciding to do. I have an invidia dp on my wrx right now and I like it (the invidia catless/tanabe back may be a tad bit to loud), I also was looking at a crucial ceramic coated dp. Maybe i'll just drive it around stock for awhile till I find a good deal.

If you didn't know, Crucial changed their DP slightly and now offers a complete CBE. See their site for details. It's still looks like a good DP.

I'll have to look into it. Most exhaust systems seem pretty similar power wise. Want to find one with good fitment and sound.

That's definitely true regarding CBE. You can find differing opinions regarding DP's though. :)

From what I have absorbed through research....The sti tends to experience some boost creep with open bellmouth design, so some people get the divorced wastegate style which crucial and invidia both make. Still deciding on getting one with a high-flow cat on it. Clean up the sound a little but it's like $200 more for the catted one, and then there is cat-back....

I believe that a DWG DP will also allow better boost response and tunability. The Crucial is also worth it for the high quality ceramic coating they use. I've had mine (older style obviously) for a few years and it's holding up perfect. I also have their old style high flow cat. Unfortunatley, it didn't seem to add much performance. I should have stuck with the stock 3rd cat, but oh well. Now I'm better set for any future turbo/motor upgrades.

What exactly is the benefit of ceramic coating after the turbo again?

Reducing IC heat soak...maintaining gas velocity.

I'm not sure how much heat soak a coated DP would stop... and if "maintaining gas velocity" were an issue in a DP, it'd be the same ~2" diameter that the UP is. Just seems like an awful expensive upgrade to a pipe for a pretty minimal gain.

You want the exhaust that causes boost creep, because it flows better. You should use proper engine management with any mods anyway.

EM alone isn't going to stop boost creep. It might help it by ramping up the WGDC faster than stock, but still, if the wastegate is 100% open and the boost is still building, no EM is going to open the wastegate more. The right answer is to port the wastegate housing on the turbo.

It doesn't solve the physical issue, but you can make it so that you don't get fuel cut.

...or it reduces the efficiency of the WG port by creating more backpressure...

No, it wouldn't.

DP's are large in diameter in order to allow a specific type of turbulence in a "collector" area as this actually spawns a cyclone effect that helps keep the velocity up. Unfortunately the WG gasses don't benefit from the turbulence and by bypassing that turbuland area of the DP, a DWG will increase the WG's efficiency.

And it does help with heat soak. Many bare DP people have wrapped their DP purely due to TMIC heat soak and engine bay heat.

http://www.crucialracing.com/products/turboblack.php

This one is looking pretty good. I want to try to find some people that have it to see if the fit/finish is good. Price looks pretty good.

This site has a lot of info as to what the coating does if anybody wants to check it out.

People are just starting to install the newly designed system. I'll let you know if I see any reviews up at WRXFanatics, but you might keep your eye on NASIOC for what would probably tend to be a less biased review. WRXF is owned by Jeremy who also owns Crucial Racing and we tend to sound like a bunch of fanboys over there.

lol, alright. Well, in the meantime let me know if you are able to get any discounts for me :)