My FD failed the emissions testing up here (BC, Canada) a couple of times. I've done the obvious (oil change, plugs, plug cables, fuel filter, etc) but it still fails. Now I have two weeks before the car is basically uninsurable, so I'm getting a bit panicky. My only mod is a downpipe, and my mechanic says I need to put the pre-cat back on for it to pass. So I searched here, and seems like all you Cali guys get the same test as we do in BC and pass with a downpipe. Only other (easy) 'tricks' I can find when searching are detaching the purge cylinder under the intake and dumping methyl hydrate into the tank, which he says I shouldn't do. So questions: is the pre-cat such a big deal, given that it's for cold emissions only, which BC doesn't test for. Also, Methyl Hydrate - can it do damage, and how much to put in? I was thinking half a gallon in half a tank of fuel, or do I need more or less?

 

you could alwasy buy an aftermarket ecu and fubar the maps to be emisssions legal.

read here:
https://www.rx7club.com/showthread.p...ight=emissions

 

There are many causes for a failed emissions test. With a downpipe, the main cat must be fully warmed up for the test -- this means going out and beating on the car for several minutes before the test...

Several things could be wrong -- ACV, failing main cat, air pump not connected or functioning, bad air/fuel filters, etc. If the tester goes into boost during the run, you will fail. I suggest either going through the FSM for probable causes or take it to a knowledgable rotary mech for troubleshooting.

 

Hey Ratchett, I've had a few problems with AirCare in the past too when I use to own my Turbo II. So a few questions for you, 1. who's your mechanic...Are you going out to langely to work with Steve or somewhere else? 2. (as noted before) You made sure you cat was hot when you tested? 3. have you already used your 3 month (one time use) pass?

 

The testers here are ex-Mcdonald's employees and generally don't know how to drive any car, let alone something like an FD. Both times I've gone in, the driver's had trouble, almost coming off the dyno one time. Needless to say, it's always gone into boost when they've driven it. So if I disable the boost it'll pass? Everything else is fine with the car, my mech's pretty good, and he's even willing to put a pre-cat on just for the test, I was hoping I might find another way to pass without doing that.

 

Chris at Eunos... and yes, made sure it was hot. And I've got about 2-3 weeks before the 3 months expires. Mostly my fault, I've just been busy doing other stuff, didn't get around to even thinking about the $&*&$ aircare until this week.

 

2 suggestions:

1) slightly pull the crossover pipe out of the y-pipe coupler, this will prevent the car from going into boost, when under boost the car is extremely rich

2) make certain whoever is driving you car on the dyno to keep the rpms under 3050 rpms, over 3050 rpms and your O2 feedback/ACV control are out of closed loop...i.e. doesn't care about emmisions

 

Just put 2 gallons of Danatured Alcohol and it will pass easy.

 

slip the guy who makes $8 an hour a nice grant or a franklin and you should pass

 

You know, I would if I thought I'd get away with it. But these testing stations are sort of 'official' establishments, quasi-government, not like the ones in the US that are privately run... I think passing over the canadian equivalient of a franklin would be met by a stony stare... at best. But hey, if someone knows different....

 

Were you close to passing? Canadain Tire sells an additive called "Emission's Reducer" made by Pennzoil. It's like $9. Maybe it's B.S. but it's always worked for me. And if you don't pass they'll give you your money back.

 

Hey books.... thanks for the tip. I guess what I want to do with the crossover pipe is create a leak, right, as opposed to pulling the thing out all the way... can I screw anything up royally by doing this (ie hot gasses flying all over the engine compartment where they shouldn't be)

 

Actually you can pull it all the way out all the way. Just let it sit there so it appears as if it is connected. If you have a visual inpsection it is difficult to see that gap. I am not 100% certain no damage will occur, but I'm sure many drivers have had that coupler fail while under boost or have the pipe pop out with no ill effects.

I certainly would stress to the driver not to exceed 2,500 rpms. I datalogged my inspection and I repeatedly told the driver not to exceed 2,500 and he went up to 3,5xx. Again after 3050 the fuel mixture will be richer.

 

Actually you can pull it all the way out. Just let it sit there so it appears as if it is connected. If you have a visual inpsection it is difficult to see that gap. I am not 100% certain no damage will occur, but I'm sure many drivers have had that coupler fail while under boost or have the pipe pop out with no ill effects.

I certainly would stress to the driver not to exceed 2,500 rpms. I datalogged my inspection and I repeatedly told the driver not to exceed 2,500 and he went up to 3,5xx. Again after 3050 your emmisions will suffer.

 

Im in the Seattle area and I just had mine done 3 days ago and I passed with flying colors. Most of my readings were probably 10-15% of the maximum allowable - lots of headroom.
I have a downpipe into a stock cat into a racing beat catback dual tip.
Stock air box with additional custom inlet thru a k&n filter.
Using a PFS PMC on my #1 setting.
I took a 30 mile run on the freeway prior to the test and let the engine stay hot (didnt turn on my cooling fans).
Had new spark plugs in 2 days before the test also.
chuck

 

Thanks for all the help. I don't think it’s the condition of the car, because the engine's fairly new and I just spent a wad of cash last month on a new emissions harness and bunch of other stuff. I'm just failing HC by a whisker and CO by a little more so I think my main cat is OK. And all the general maintenance things (plugs, filters, etc) have been done so it's not those. So back to this precat… if it's going to get me a pass, I'll just go and get it bolted on for the test, but if it's going to fail anyway cos the tester can't drive the car and puts it into boost all the time then what's the point? I'm just unclear on what the precat really does and how much it helps in reducing normal operating temperature emissions.

 

Why do you think your main cat is OK? If it were OK, and the air pump is working and hooked up, you should pass, as everyone has said, without the pre-cat, once the car has been thoroughly warmed up.

 

Well, they didn't really say it would pass without the pre-cat if the main cat is OK. There were suggestions about how to essentially trick the testing equipment by disabling the boost, adding alcohol to the tank, etc, but I didn't get the impression that if my main cat was OK I'd pass without a pre-cat. My only assumption here is because I'm failing by a very small amount, my main cat is still working, but perhaps that assumption's wrong. What I want to avoid when I go back to my mechanic is wasting his and my time with him bolting on the precat in the hope that it'll pass emissions, and then for it not to pass, then we have to try a new main cat, and so on... I'd rather just do it right the first time.

 

Here's my logic:

Other people have (in this and other threads) stated that they passed emissions with a DP, etc., with huge margins to spare (emissions less than 20% of the max allowed). If you are barely failing, that means your car is emitting at least 5 times what it should. Therefore, IF the testing technique is not to blame, you have something seriously wrong, such as a failing main cat, bad O2 sensor, etc.

Hope this made sense.

 

Yes, replace the O2 sensor if it hasn't been done recently (past year). I've heard from reliable sources that the ECU uses the O2 sensor to determine air/fuel mixtures at partial throttle. When at full throttle (and maybe at full boost also), the ECU goes into 'open loop mode' which is very rich.

Emphasize to the tester that your car is very powerful and doesn't need a lot of throttle to accelerate (if this is a dyno test).

You might want to try this, it's a bit involved, but it might be what you need if you can't get them to keep their foot off the gas:
http://www.mantissaconsulting.com/et...ion_switch.htm


-s-

 

Back in Pennsylvania, before I moved to 'Vegas I had to pass new PA visual inspection and later Nevada (Clark County only) emissions tests.
My exhaust setup at the time was a new 3" stainless Pettit high flow cat and cat-back dual tip system W/ an M2 stainless downpipe. I called Random Technology and bought their METAL matrix ultra high flow cat for a pre cat. It was 3" in and 3" out and the main body was only 4" in diameter. Overall length was about 9".
My fabricator welded it in the downpipe perfectly. I also wrapped it with Themo Tec tape to help keep heat out of the engine compartment.
When I got to 'Vegas the car passed emissions with flying colors. We have "50 State" standards here for emissions, meaning California standards.

It cost me $400. for the cat and the labor. Well worth it.

 

Just wanted to let you know that the car finally passed after getting a new main Cat (Bonez). No tricks, no alcohol (except in me), no pre-cat.

Readings before Cat were (sorry for the metric stuff)

HC: 0.54 gm/km (fail)
CO: 10.95 gm/km (fail)
NOx: 0.73 gm/km (pass)

After the cat:

HC: 0.18 gm/km
CO: 2.09 gm/km
NOx: 0.15 gm/km

Thanks for all the tips and suggestions, and good call, DaveW!

 

You have a BAD catalytic converter. I have seen cars with LARGE streetported engines with ALL the bolt ons pass California emissions...easily. They burned so clean they were almost considered "green " vehicles. All that was required to pass was a new cat, they failed with the old stock cat.

 

There you go! Same cat as well!