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3.0r 3rd cat delete legality and emissions?

PostPosted: Wed Jul 12, 2017 12:08 am
by edenotto9
Hey everyone.
From searching around the forums i have discovered that it's a common mod for 3.0s to delete the 3rd cat. However after reading the legislation im beginning to have second thoughts on how legal this is, so i thought i would make a post to get some second thoughts.

Also putting legality aside, does anyone know if removing the 3rd cat would cause the car to fail an emissions test? From what i have heard its a rather worthless addition to the system, but then why did subaru include it in the firstplace if it doesnt impact the emissions?


Thanks
Eden
(forgive me if i made any mistakes in posting this, first time posting)

Re: 3.0r 3rd cat delete legality and emissions?

PostPosted: Sun Jul 16, 2017 1:41 pm
by Swipez
To be honest with you, without the "oh if you do this, and this" BS, by deleting the 3rd cat, you will definitely change the emissions, therefore being rendered 'illegal'. There is nothing you can do about that other than paying big money for a professional to sort you out a full exhaust system that can bring you greater performance while maintaining the same emission values. But that just isn't viable for 99% of us.

So let me say this, by deleting the 3rd cat (and if you are running aftermarket headers) you will more than likely get a new rasp tone above 3k rpm that sounds dreadful. If you really want to delete the 3rd cat, I'd recommend doing other supporting exhaust mods while you're at it, including a nice high quality resonator to cut out the unwanted frequencies. I have spent a LOT of time and money on different exhaust set ups on my 3.0L. I have now concluded that having raptor headers>2x hi flow cats>vibrant performance resonator>oval straight through muffler>twin rear mufflers gives me all the added tunable performance and is under the sound limit for nsw road cars of 90db, but still sounds fantastic.

If I were to get emission checked, I'm sure my car would fail as it is flowing far too much compared to stock, and with 200 cell cats. However, the likelihood of me getting referred to a full test like that from a police officer is near non existent, due to how quiet my car is, and I have all necessary parts like cats, mufflers and resonators. So on the side of the road, a police officer wouldn't t be able to defect me unless he had x-ray vision and the ability to recognise cell counts on the fly, which just will never be the case.

Just don't be a wanker on the road and you'll be trouble free 100%.

Hope I've helped,
Jordo.

Re: 3.0r 3rd cat delete legality and emissions?

PostPosted: Tue Jul 18, 2017 11:21 am
by tom_kauf
I agree with Swipez, it is technically illegal. But I didn't know any state in Australia had emissions testing. I hadn't even heard of police being able to make you get one, but I'm only familiar with QLD rules. So it sounds like some states do have that.

To give you some idea of how good a new aftermarket 200cell Cat can be: The factory down pipe on my GTSpecB had 2 cats (at probably 700cell or more each). My aftermarket downpipe has 1x 200cell Cat. The ECU was tuned for it, but no 'Catalytic Converter Efficient' codes disabled. It didn't throw a 'Check Engine Light' for about 4 years. The first one came on last week. I cleared it and it hasn't come back since.

I don't know exactly how that compares to values at an Emissions Test Centre, but the ECU was happy with the Cat's performance for all those years.

Re: 3.0r 3rd cat delete legality and emissions?

PostPosted: Sun Aug 20, 2017 4:13 pm
by edenotto9
Thanks guys, was also wondering about insurance implications if i were to have an accident? Would i not be covered if they noticed this?

Re: 3.0r 3rd cat delete legality and emissions?

PostPosted: Tue Aug 22, 2017 9:06 am
by tom_kauf
edenotto9 wrote:Thanks guys, was also wondering about insurance implications if i were to have an accident? Would i not be covered if they noticed this?

It depends on your Insurance Policy. If your insurer demands that you tell them about all modifications, then they might have a reason to refuse to cover you in the case of an accident (if you haven't told them). My insurer (AAMI) allows all modifications that are roadworthy, without having to tell them. They specifically mention that, and only ask people to consider the value of the mods when choosing a car's insurance value.

From an environmental law standpoint, I would consider running no Cat (on a car that had them from factory) to be illegal. But it's definitely not a road safety issue, so they'd really have to be picky to deny you based on that. But if have a Cat installed (even if aftermarket), and your insurer is ok with the, then there's no issue.

Re: 3.0r 3rd cat delete legality and emissions?

PostPosted: Tue Aug 22, 2017 10:41 am
by Flat6Estate
Not a road safety issue?
Think of all the fluffy kittens minding their business on the footpath that breathe in those noxious fumes :lol:

Re: 3.0r 3rd cat delete legality and emissions?

PostPosted: Tue Aug 22, 2017 9:24 pm
by edenotto9
tom_kauf wrote:
edenotto9 wrote:Thanks guys, was also wondering about insurance implications if i were to have an accident? Would i not be covered if they noticed this?

It depends on your Insurance Policy. If your insurer demands that you tell them about all modifications, then they might have a reason to refuse to cover you in the case of an accident (if you haven't told them). My insurer (AAMI) allows all modifications that are roadworthy, without having to tell them. They specifically mention that, and only ask people to consider the value of the mods when choosing a car's insurance value.

From an environmental law standpoint, I would consider running no Cat (on a car that had them from factory) to be illegal. But it's definitely not a road safety issue, so they'd really have to be picky to deny you based on that. But if have a Cat installed (even if aftermarket), and your insurer is ok with the, then there's no issue.



But wouldn't deleting the 3rd cat (while keeping stock front two) technically make the car unroadworthy though? If I told my insurance company I cut out a cat illegally I can't imagine they would be particuarly happy to insure me. Perhaps rather than deleting the cat all together with a replacement pipe it would be better to just gut it and run the gauntlet of no one noticing it's been hacked open and welded. Any advice would be greatly appreciated.