ddub

About a year ago I went through a lot of **** trying to pass emissions. At the time my car had a bonez high flow cat and ALL emissions equipment attached and connected. I kept testing different things and even took it to a shop! Yes I got so desperate I took it to a state certified emissions shop that not only specialized in Mazdas, but they had a guy there that worked on rotaries only. They tested, replaced, and did all they could (turned out my ACV was bad too) but to no avail. At this point I could’ve gotten a 1 year waiver since I took it to a state certified shop and spent enough money, but that would’ve just put me in the same boat at this point. I wanted to get this done and figured out so I went to work. It should also be noted that I didn’t want to use alcohol in any way, shape, or form because I really didn’t feel like dumping it into my car and having to be careful and worry.

Through trial and error I ended up failing 5 times while trying to figure out how to pass, finally I got so pissed at the emissions equipment that I junked it all. I stripped off my EGR, ACV, rats nest, solenoids, even the BAC and 6pi system. I was so sick and tired of things not working, having problems, not passing, and having no idea why that I just wanted to start with a bare block basically. In the end, I passed.

Every now and then I get messages on AIM from people on the forum asking for help with emissions. They had the same problems as me with stock emissions equipment and still failing without any idea as to why. I always end up explaining the same thing to each person so I figured I’d just put it up here as a reference that I can link to, this way I don’t have to type it all out anymore either

So here goes…

What you need:
At least 1 cat (main cat) and NON-clogged precats
Split air pipe still connected to cat
Air pump
1.5ft 3/4" ID heater hose
2 hose clamps
Basic hand tools

Things to do:
Timing set to stock
Fuel system stock (injectors/pump)

First things first. With my method, which worked perfectly for me, I did not use ANY other emissions equipment. What exactly YOU do with YOUR equipment is up to you. You can block them off if you want, or merely cap the ACV. You need to at least cap all the ACV lines, the one going in from the airpump, the one going out to the split air pipe, and the other small line that I believe is there (if memory serves me). Do whatever you want with the other emissions junk and 6pi system, either leaving it or taking it out, it doesn’t matter.

You should now have the airpump still hooked up and operating and at least a main cat with a split air pipe connected. Go to an auto parts store or something and get 1.5 feet (you’ll need slightly less than this) of ~3/4" ID (inside diameter) heater hose or something similar, along with 2 small hose clamps to fit it. Hook one end to the OUTLET of the airpump and then the other end to the INLET of the split air pipe. This will allow more air to go to your cat than the ACV would normally allow. As well, this will provide constant air at idle and at cruise whereas the ACV doesn’t send air to the cat at all times. This is the first step and for some people it might be all you need to pass if you’re on the edge. If not continue.

Next thing to do is play with the variable resistor if you still have it and it is in working condition. Turn it to full lean, or as much as you can. Continue to lean it out as much as you can to where you car can still idle smoothly. You should be able to turn it almost all the way, but if your car starts to chug or want to die, richen it up a bit to get a smoother idle.

Now, with the variable resistor leaned out for idle and the other stuff set up, adjust idle. With the idle stop screw and idle adjuster screw on top of the TB (and BAC for turbo vehicles) adjust them to achieve the lowest idle you can while the car still idles. You don’t want it TOO low, if it’s too low it might die or cause other problems during the test. I was successfully able to get mine down to 500 and it actually tested at 480 during the emissions test, never died the entire drive there, back, or during the test. Theoretically the lower idle should be injecting less fuel, thus lowering emissions, that was my thinking, but to be honest I’m not sure if this helped all that much but I did all I could. For those people in states without an idle test, ignore this.

Once you have your idle lowered (for people in states with an idle test) set your TPS back to stock! If you don’t have an idle test make sure your TPS is set correctly.

Before the test take the car on the freeway and get the exhaust nice and hot. Also, as a note and precaution, I have no idea how long the cat will last with getting more air than it is normally meant to and I don’t know what this could do. So, that being said I take no responsibility for anything happening to your cat. My suggestion is to do what I did. Install and set up everything, go for the drive on the freeway to get it hot, take it to the emissions place to get tested, bring it home and stop driving it. Now either park it until you have time to put everything back to normal, or do it right then. This is just a suggestion, it could last a while, I don’t know, but I’d rather be safe than sorry so I swapped it out before driving again. I was able to swap and have everything set up, go get tested, come home and swap it all back off and get it back to normal settings in 1 day. It really isn’t hard at all, and I did it with swapping the cat in/out and the airpump in/out as well. If you already have this stuff in there it should be really easy.

Here are a couple reference pictures, very simplistic. First the airpump with heater hose hooked up to it.




Now, a very shitty mockup of what the airpump will be like hooked up to the split air pipe and cat. Since I don’t have it in my car anymore I just set it up on my chair with the cat on the floor, enjoy





I think that’s everything, if it’s not I’ll add to this later. Any questions, comments, or concerns? I’ll be glad to answer or respond to anything you have to say. Also, if someone out there has a disagreement with me then please go ahead and let me know, discussion and information is good for everyone

Just a note, I did this mainly because I’ve had a lot of people with emissions problems contact me and this is the same thing I always suggest when ALL ELSE FAILS. I was also bored

Enjoy!

Oh and a couple things I forgot. I premixed during emissions, didn't effect it. And also, here are the results of my emissions test after all this. Before I was failing all areas badly.

Idle HC Limit = 220
Idle HC Test = 86 PASS

Idle CO% Limit = 1.2
Idle CO% Test = 0.05 PASS

Cruise HC Limit = 160
Cruise HC Test = 73 PASS

Cruise CO% Limit = 1.1
Cruise CO% Test = 0.01 PASS

Andrew.

iTrader: (4)

Hey ddub is that just a generic cat right there or the bonez superflo system? I was thinking of getting a generic one with same piping but i've heard with the rotary engine you need a special one because generic ones will just burn up or something, tru?

ddub

Bonez high flow main cat replacement. A generic cat can work, but if it does it wont be for long. Really no way to tell how long exactly. Some people have better luck than others and they last a long time, other people blow them out really fast, so you can risk it if you want for a cheaper "universal" high flow cat.

Jager

iTrader: (10)

Nice write up. Thank god I'm don't have to worry about it here ;o.

ddub

Yah not all of us have that priviledge

I'm just glad I don't have visual at least.

BlaCkPlaGUE

holy ****, looks like you passed with flying colors my man! wicked article, ARCHIVE ARCHIVE. This is much better than the alchohol test with the vaguest description ever in the faq.

You could pass the visual by leaving the stock **** on I spose, its just not functioning.

Do you have any tips for people with the safc by chance? I would think its alot more effective to use the safc than the variable resistor no? that is, if you have one

Im also curious to know how adding more air affects the cat. Personally I don't think it does anything negative, might even prolong life.. who knows. Maybe someone can chime in with some facts on that.

nice work ddub

RotaryEvolution

iTrader: (30)

even if you have cat failures the federal government regulates that they provide a 5 year/50,000 mile replacement warranty.


i never really understood what a "high flow" cat is, the bonez looks like any current style cat you can buy at an aftermarket vendor, i suppose it just sells better if they label it a "high flow" cat...

ddub

Thanks, I did pass pretty well didnt I

I didn't like the alcohol way, just didn't seem very safe to me especially because they say to drive very "gingerly" and be careful, and imediately fill up with gas afterwards. So I went another route.

Yes of course an S-AFC will help even more! I didn't put that part in there because I wanted to write something up anyone could use, even those without a fuel piggyback. With the S-AFC you'll just not use the variable resistor, and instead you'll subtract as much fuel as you can at idle to the point where it is still idling somewhat smoothly. You can also leave yourself with a higher idle and just keep leaning out the s-afc as the idle drops further and further, and stop before it wants to die completely. Then you can lean out say (on an N/A) -10 at 1k to 3k rpms for the cruise test. With a turbo be careful not to be subtracting fuel near where boost might come on, don't want to detonate.

Thanks

ddub

High flow cats are just supposed to be better flowing than a conventional cat. I've seen dynos of high flow cats providing more power than a normal cat, hence the name "high flow"

Whether or not it actually does, though, is unknown to me. I've seen high flow cats versus stock ones too and looking inside you can definitely (at least I can) see there is less "junk" in the high flow one.

Also, the bonez isn't just marketed as high flow and that's the only reason to buy it. The rotary runs much hotter than normal piston engines, and this cat is meant to withstand it. I've seen normal universal high flows blow or clog in a rotary eventually, the bonez doesn't seem to ever, at least I haven't heard of it yet.

RotaryEvolution

iTrader: (30)

but by conventional are they referring to older style pellet cats or large diameter stock ones? most aftermarket cats are almost identical to the bonez high flow cat, hell if i painted one silver i wouldn't be able to tell the difference and the guts are all the same material.

ddub

By conventional I mean stock, even new stock ones.

Almost all aftermarket cats I see are called "high flow" as well as the bonez. It's not anything new.

RotaryEvolution

iTrader: (30)

ahh, i just wondered why most people spent $300 for a cat that should cost $75-100.

anyways, sorry for hijacking the post. i just thought i would get some feedback on cats since a good working cat is the base building block of a good smog.

Havoc

I have a Hi flowed Cat. Basically it flows more and is less of a restriction in your exhaust system. the only reason I had it put on was over here we have no emission testing, but you need a Cat to get over the pits (of any sort, weather it works or not ) so why not get one that help out your Hp

Funkspectrum

iTrader: (5)

I was told to use the Mustang SVO cat for turbo engines. It has a 2.5' inlet/outlet.
I haven't tried it yet but I'll let you guys know the results when I do....

jn2k108

does massachusetts have a visual?

Wankel7

In your list you said a pre cat was needed... I was under the impression that the precat simply scrubed the start up emissions?

James

Turbonut

iTrader: (1)

Great writeup. I just passed Jersey inspection last month (S5 TII) with a G Force ecu, Bonez hi flow cat and all emission equipment in tact. Numbers not as good as yours, but HC Cruise was 125, not really close to failure though.
One item to keep in mind which has been said many times, is that if all emissions equipment has been removed, and no visual in your area, use an electric air pump hooked directly to the air tube.

TKE

Why do you people spend so much time money and effort on passing emissions?

In my neck of the woods, you just find a run down looking shop in a shady neighborhood and slip the guy 50 bucks problem solved.

Dltreezan

iTrader: (3)

why cant you just make a custom pipe with 3 or four cats for the test only and then take it off when done? Or would that drastically afftect backpressure?

Mindspin311

Awesome write up as I just got my S5 TII and need to pass emissions. Thanks for saving me the trouble of searching

HAILERS

Ethical people vs the non-ethical.

ddub

I said this:

What you need:
At least 1 cat (main cat) and NON-clogged precats

What I meant by that was that you at least need 1 main cat (and no precats) and if you have precats they need to not be clogged. I passed my test with an RB header and a bonez high flow, no pre's.

ddub

Money? I had the bonez high flow cat already and I spent $0 except to buy the tube from the airpump to the split air pipe to pass, so that was like 5 bucks at most maybe? Only thing it took was time, my time.

And where I am there are no "shady" places that do that, and if you try you get in a lot of trouble. Even if there are ones around here I wouldn't do it.

Turbonut

iTrader: (1)

Not trying to start a war, but what's the difference between paying somebody to get a current inspection, or removing all the emissions, then supply direct air to the cat so that it will pass, then disconnect the air tube/pump, which is against the law?

ddub

At least I still passed the emissions test that's somewhat better. Besides, my problem was that my ACV had taken a **** and it wasn't working properly. So it was either figure out a way to pass without stuff, try to find a good condition ACV used which would be hard to know over the internet (for sale section) if it's good or not, or bite the bullet and buy a new one (expensive I'm assuming). I figured this was my best route. Yes it's still illegal in a way, but it's less illegal than paying off an inspection person.