It depends on the state and how their testing equipment works. Normally you can get by with just one.

 

It depends on the state and how their testing equipment works. Normally you can get by with just one.

+1

To elaborate a bit: different states have different emissions checks. Almost all states (if not all) use the OBDII port on your car to check emissions. Some states (NY included) also have a visual inspection of the exhaust as well. If no visual inspection is required, some people may get away with catless exhaust, but with a visual, you'll fail.

Best advice would be to read up on your inspection rules, and follow them accordingly. If it's a TurboXS TBE, you could buy a high-flow cat to put into the exhaust, instead of having to purchase a brand new DP.

 

Thanks. As far as i know it is a 3' Helix TBE, and in DE they use ODBII. Thanks.

 

California sucks when it comes to emissions testing. There is a visual and I think if you run aftermarket cats on it they will fail you because they aren't factory. I might be wrong on this but everytime I've ever looked into purchasing an aftermarket high flow cat there has always been a note stating not for use on California vehicles.

 

I might be wrong on this but everytime I've ever looked into purchasing an aftermarket high flow cat there has always been a note stating not for use on California vehicles.

currently there is no way for a smog tech to point to a cat and say it's not factory, cuz how can they KNOW every cat ever made. the reason the sites state that they are not for use on CA vehicles is because nothing short of an OEM cat will pass the super-stringent emissions tests. they have to state that so no one will try to sue them...

 

Good thing i dont live in CA then, another question. Is there any special map i should run while im going through emissions, since the car is practically already stage 2?

 

Good thing i dont live in CA then, another question. Is there any special map i should run while im going through emissions, since the car is practically already stage 2?

An aftermarket DP + EM is StageII. You should be running the StageII map. If you're worried about your inspection, then get a stock exhaust and replace it back to stock (both exhaust and ECU) before your inspection, and then go back to StageII

 

To give the short answer to your question....all of them. If you have a catless uppipe, it's doubtful they'll fail you just for that because most inspection stations look for the after turbo cats in the exhaust portion, not the preturbo piping (plus the STi has not cat there, so you might be able to say it's a factory pipe, etc, etc).

The long answer is, you need however many cats are needed to

A: Pass tailpipe emissions if that's what your state does (in my experience, yes, a catless car can pass if it's tuned properly).

B: Not throw a code on your ecu. This means either a reflash like accessport (as mentioned) or a mechanical resistor fix in place to fool the ECU.

Basically you just need to find out what the state mandates for inspection. This can be accomplished by asking someone in the local forums. I would recommend trying to get with other local clubwrx members and find out what they have done. Worst comes to worst you can just find the shadiest inspection shop and try to slip the guy like 200 bucks to pass you. Yeah it's stupid, it's illegal, blah blah, but after you drive off his inspection station it's your responsibility to have DOT compliant parts on your car...what says you couldn't have installed the catless exhaust 20 minutes after he inspected your stock car....see where I'm going with this?

Best of luck,
~Tim

 

As far as I know, it's illegal to remove/modify any catalytic converters that come OEM on a car.

Whether or not it passes emissions, it's still illegal.

 

I don't know about you but most of the aftermarket cats I've seen don't look anything like an OEM. Also, I believe the law is you can't remove a factory catalytic converter under 100k miles.

 

what you need to have and what you can get by with are two different things.

in most states with emissions inspections, you need to have all factory cats in factory locations. what you can get by with is more up to the person doing the inspections.

 

Just wanted to let everyone know that I passed the emissions test. No visual inspection here in DE.

 

If I remember right It's mileage to replace a cat before 50,000 miles. :barf:

A while ago someone asked the same question here in OR. Passed just fine. It sounds like the rules are similar in DE.

 

If I remember right It's mileage to replace a cat before 50,0000 miles. :barf:

A while ago someone asked the same question here in OR. Passed just fine. It sounds like the rules are similar in DE.

i think you meant 50,000 which is still super low. on a clean running engine with no misfires (they kill cats) a factory cat can last 100k easy and 150k isn't out of the question.

 

^ Thank's for catching the typo. If I remember it's against Federal law to change a non functioning cat.

The cats last much longer, but I did have one fail at about 120,000 miles back in collage. Real pain to diagnose. The car had a little rattle and every once in a while it would NOT accelerate. Turns out the cat had rattled around to the point that is was about the shape of a baseball. When the car accelerated and the honeycomb was aligned with the flow and everything felt OK. If the core was perpendicular to the flow that it corked the exhaust. When the local Audi dealer quote $400 I broke out an old cold chisel. Car went through the local snifter test just fine, but they did look underneath...