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'02 WRX exhaust and smog advice - central Cali

7K views 8 replies 4 participants last post by  arcticscythe 
#1 ·
Hello all -

I've recently purchased an '02 impreza WRX with a 3" turbo back exhaust with no cat, sti injectors, and running added boost (18psi). Open source tuned. The guy I bought it from was supposed to set me up with is tuner friend who was going to put the stock exhaust and induction back on to smog it. Well, he's since flaked on me and I'm left with what seems to be a great running and pretty quick impreza that I can't smog. I'm familiar with aircooled VW's yet have always liked Subaru engines due to their boxer layout and swapability into VW's, so I bought one for a daily driver.

So, my question to you all from a Suby newb, what the heck do I need to do to get my car smogged ? I'm in Modesto and there are no shops around here that I know of to offer advice. The kicker is, I've only got 600-$700 left to get this smog issue taken care of. Do I need to find a full stock exhaust setup plus stock injectors and a retune? Is that my only option? What else can I do?
 
#2 ·
After 3 rounds (once every 2 years) of switching out my aftermarket turbo back exhaust (this includes the downpipe) with a stock system, this year my tuner said it was not necessary due to some "minor changes" in the CA smog procedure(s). However, my tuner did mention that the smog test center that they sent me to a shop that has a tech who "does not see very well."

I have always been able to pass the sniffer and readiness tests. In fact, my car was cleaner after my custom tune than with the stock tune. The problem for CA cars is the visual inspection.

My father has a 12 year old Nissan Altima, which are notorious for failing catalytic converters (among a whole host of other things). For the past 2 inspections, he has found a local smog tester that has been able to get the car to pass. Not that he has done anything illegal, just that he has diagnosed the car, reset the computer, and done the test at the ideal point (readiness checks have completed but ECU hasn't tripped any CELs, a window that is only "open" for about 20-25 miles on the odometer).

My point is that if you can spare the time, get out there (internet, phone, and/or physically) and talk with some of the owners/techs and the smog test stations. Take note of what kind of cars are frequenting (and sitting outside) the different sites. There are guys out there that will be straight with you and help you without needed to feel like a criminal. Those guys (or gals) are the ones you will want to build a relationship with.

...you shouldn't need new injectors.
 
#3 ·
@Zachary Ham,

My personal feeling on CARB aside I still think a Cat somewhere in the system is good for everyone. It carries a little bit of back pressure thats good for the turbo and it burns off some of the garbage that makes the sky milky and opaque. If you pickup a reputable catted down-pipe it should only set you back a few hundred bucks and depending on your particular tune you may not even have to re-tune. Even if you do need to re-tune it will be worth it to save the rest of the world the air pollution.

If I was in your shoes I would get a Catted down-pipe and have it tested. Even High efficiency Cats if properly warmed up will pass the sniffer in California. The part you might have difficulty with is the visual inspection. I wouldnt worry about a visual inspection smog tech calling you out on your injectors but they have been hard on me over intakes in the past.

If your engine bay looks mostly stock then most smog shops will pass you. It doesn't hurt to drive in dressed better than you normally would with classic rock on the radio. Ive been passed on a few cars that had no business passing because I pulled in after work wearing a smile.

As far as the actual test you might get a pass easier just because you drive an AWD vehicle. when you take it by most smog shops they wont have a 2 drum dyno so you will be tested on flat surface with the ECU and the sniffer at idle. That means that you will need to have the few hundred miles on your ECU for their test to read and as long as you dont have any CELs you should be fine.

TLDR, Be nice to the environment and your fellow Californians and grab a high flow catted down-pipe. If your lucky your tune will still work. Put a few hundred miles on your ECU before you take it in and always be nice to the guys at the smog shop : )
 
#4 ·
Thanks for the replies.

So wit a decent catted downpipe I could very possibly pass smog at idle? I believe my '02 is supposed to have 3 cats stock, and it currently only has one (before the turbo I believe?) so I wouldn't pass on visual because of that, right?.

Is there a catted dowpipe you can recommend? I think I would like to leave the catted pipe on there, so I'm looking for decent quality within my ($600) budget. I assume I would just unbolt my current cat-less downpipe and put in the new, and it should all connect length wise with the rear end pipe that goes to the muffler (mid pipe?). ?

Also, how will my car react performance wise? If it require a re-tune how can I tell? Engine damage if driven or will it be alright without a re-tune for smog? It seems to run pretty well now and I'd hate for that to change. Will it throw a code or the check engine light?
 
#5 ·
If they bother to even look under the car, then by the letter of the law you should not pass the visual. But Jason makes a great point about being a "nice guy". Don't go in acting like you are trying to trick the tech. Just be respectful and give them only the information they ask for. I once had to explain to the tech what the big radiator looking thing on top of the engine is, and I did it in a polite and non-condescending manner. Remember, most techs are not mechanics.

FWIW, I pass the sniffer test (with flying colors) with only one cat (in the downpipe).

After this situation is finished, please start saving money in order to replace your up-pipe with a non-catted one. If the cat in the up-pipe starts to deteriorate, the loose pieces will go right into the turbo and likely cause an even more expensive replacement (of your turbo). Please note that this suggestion is not related to your question about passing smog.

I'll let those who are more experienced in exhaust parts, their quality, and their cost tackle your other questions.
 
#6 ·
I would definitely pull that CAT in the up-pipe, Im sorry I didn't catch that earlier I assumed you were totally cat-less. The stock CAT in the up-pipe can "Grenade" and send shrapnel into the turbo : ( an up pipe without a cat is essentially a mandrel bend piece of pipe with flanges welded onto either side, it should be priced accordingly.

As for a decent catted down-pipe Invidia seems to be the most popular on these forums, I personally like the Cobb down-pipes because they use the same gaskets as the stock unit so it should be very easy to install. Essentially every company that handles exhaust makes a down-pipe. Look for a high flow CAT media and you should be in a good spot.
 
#7 ·
Okay, so with a catted down-pipe I should pass the sniffer. Looks like the hardest part is going to be finding a shop/tech who needs glasses. The engine bay in my car looks relatively stock, the intake is stock except for the tube/hose as been replaced with an aftermarket blue one. There are non stock hose clamps everywhere that will grab attention. Also, I forgot to mention I have an atmospheric? BOV that is easy to see and hear (over 3k rpm) as not stock.

I will replace the up-pipe ASAP, luckily they look relatively simple and aren't too expensive. I imagine I would get faster turbo response wit a cat-less up-pipe also?
 
#8 ·
I would try to find a performance shop to do your inspection. They tend to "ingnore" some things. And by having that Cat at least your trying haha.

Also is the BOV full venting or is it a 50/50? You should really have one that at least recirculates a little.
 
#9 ·
Clamps and colored hoses might be attention grabbers for guys like us but for most inspection techs as long as they all match nothing will look too out of place. As long as everything is matchie matchie and it all has the same layer of grime on it most techs wont have a problem. These folks are not Subaru performance techs, they are paid by the state to collect another additional tax every few years.

Even 1 CAT will help the environment quite a bit, its really the diffrence between pushing out flamable fumes and burned hydrocarbons. I dont like CARB as much as the next guy but I think a CAT goes a long way towards keeping our air clean.

As for your Blow off I would set it up to full bypass unless you have a tune designed to run atmospheric. Most guys throw a blow off valve on their cars because they sound cool, with a MAF setup you run the risk of creating a temporary rich condition which is not good for the engine.
 
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