I am at a loss for how to proceed with respect to getting by smog.

Car runs well. 110k Miles on the odometer. New 02 sensor, new catalytic converter (magnaflow #94106 2.5 inch universal fit model), new air filter, new plugs, new wires (NGK blue). Oil changed about 600 miles ago.

Compression is 160, 165, 167 and 170 across cylinders 1-4.

I also have a wideband and the 02 is reading perfect stoich oscillating beautifully around 14.7 AFR during all parts of the test. I have not done a leakdown test but i would imagine there would have to be a lot of blow by to cause excessive HC's. Car does not smoke at all on cold start. Runs very smooth as mentioned above. Slight oil leak in rear main seal. Consumes about 1 quart every 3000 miles.

Coolant sensor checks out fine with voltmeter (200-300 ohms at operating temp). No fuel in FPR vacuum line connected to intake manifold so i assume the diaphram in there is fine. PCV valve clicks when shaken (Is there another way to test this??).

The car does have a greddy turbo kit on it with 2.5 inch exhaust from the turbo back. Supra 305cc injector and Emanage for fuel and timing. For the smog test, the stock ECU was used along with stock 1.6 injectors and the wastegate was wired open to prevent any boost. In essence its now like a bone stock miata with a bigger exhaust and a cone air filter.

I am hoping that someone has some suggestion of what could possibly be the problem.

I keep failing the idle test with high hydrocarbons. The numbers are the following:

The maximum allowable is 115 PPM HC and 0.92 CO

1. 233 HC 0.62 CO
2. 157 HC 0.65 CO
3. 178 HC 0.13 CO
4. 141 HC 0.56 CO
5. 151 HC 0.50 CO


The test is performed by warming up the car by idling it at 2500 RPM in neutral for 30 seconds and then the exhaust probe takes a measurement once a second for another 30 seconds. The test centre takes your best 10 second average measurement. I have the graphs and there are no spikes, just a smooth flat line above the maximum allowable.

Test #1 is daily driver test with nothing special done to the car running on 91 octane timing at 10 degrees BTDC.

Test #2 is 87 octane with 20% denatured alcohol, timing 10 BTDC

Test #3 is 87 octane with 35% denatured alcohol, timing 6 BTDC

Test #4 is new catalytic converter, new oxygen sensor and 87 octane (no denatured alcohol), 6 BTDC

Test #5 is new cat, new 02 sensor and new 1.6 fuel injectors, timing 6 BTDC.



I am now paying $35 dollars a day for insurance until it passes. At this point i am ready to do anything to get it to pass short of destroying the motor.

I am thinking that maybe that CAT just aint doing its job well enough. I noticed Ben bought the same CAT when he was going through this last year and he too failed with it. I was thinking of slapping on an old stock exhaust with OEM cat, maybe that would help. However it is BRAND NEW so i cannot believe it would be that bad.


THANKS FOR ANY ADVICE ANYONE CAN PROVIDE,

Regards


P.S. I am in the Vancouver, Canada locale so if anyone around there knows any trustworthy aircare certified shops that will give me a conditional pass and take into account my receipts for the work already done and not scam me then let me know.

 

Before you take it to the smog place, retard the timing to 3* or 4* BTDC. Its gonna run like crap but Im pretty sure its gonna pass. This tip was given to me by the smot tech that Ive been using for the last 5 years. Sometimes he retards timing to 1* BTDC.

 

Background- I've never done any emmisions testing so I'm kinda talking out of my ***...


I say put a new (used) stock catalytic converter on it. Performance ones are a compromise. They flow better, but don't "work" as well. Some are for passing visual inpection more so than anything. Some will work ok, but not as well as OEM, yet may get you the right numbers to get through some test. But I doubt any performance catalytic converter will match ALL the numbers testable when compared to a new stock cat. I bet a new cat will solve all your problems.

Also- this works too.... Warm the engine up WELL. Put the motor at ~ 5K and empty a can of carb spray through the throttle body, keeping the throttle as wide open as possible and slowing the spray of carb spray as the engine dies from too much fuel. Will clean the motor up a lot. water works too. Then new plugs and reinstall cat and go test.

 

What plugs you running? Heat Range etc.. I bet you still have your colder than stock plugs in it. I always like to run stock plugs for E-Test. If that does not work try the alky trick with the stock injectors as tested in #5

 

I'm in Vancouver and running a turbo 90 as well so I know what your dealing with.

First, unless your car is so low you can't get onto the rollers there are two parts to the test for a 90.

The first part where they have the car running at 40K on the rollers it part of the test. They measure Hydrocarbons, Carbon Monoxide, and NOx. After that, they test the Idle and measure for Hydrocarbons and Carbon Monoxide only.

I am running a full standalone, so I have more freedom to adjust things, but more things to mess up and not be stock. I'm also running a non stock and questionably useless CAT.


To start, you have to idle and run along at 40K fairly lean. I set my car to idle at something like 16 or 17:1, and run around 16:1 at the 40K in 2nd, stock timing. The High hydrocarbons and CO are a direct result of to much fuel, misfiring, and unburnt fuel. the car is far more likely to misfire at a lower RPM, so set the car to idle high, like 1100rmp. Also, run 87 octane. It is easier to ignite and will burn faster and more completely at low power levels.

If you are running an oiled air filter, that can add to Hydrocarbons as well, but more so with a filter that is really soaked with oil. I run a K&N without any problems.

Right now your problem is that you are running far to rich for the test. What is different with your setup from stock that would cause this? You have the stock ecu, what about the fuel pressure? What about the NB02? What about the AFM? You need to lean the car out to be able to pass the test.

If you search the Vancouvermiatas.com forum there is a fair bit of info and experience with this Aircare Bullshit (my 1.6L isn't allowed, but a giant SUV with twice the pollution is?). Feel free to PM me there with any questions, same user name.

 

Mathewniceguy,

NB02 is brand new. AFM checks out. Idle fuel pressure is 41 psi using walbro 190LPH HP pump.

The car has winter studded tires on it so aircare cannot do the running test, only the idle test as described above. If you ever need to borrow them to do your test, msg me. There legal in BC from October to May. I actually had better numbers doing the running and idling test before the snow came. I was only failing HC during the 40K test, but strangely enough passing the idle test. I didn't even post those numbers. Now i cannot pass the dam idle test, i thought i had aircare beat when i put the studded tires on! Thats why i think maybe the CAT is a POS.

Regards

 

change your oil that always brings down HC, they may check your timing so be carfull with that one, it does work but the guy failed me for pulling to much out.

 

Studded tires ah? Huh, never heard that trick, sounds like a good one.

I know your fuel pressure checks out but I would still be a bit worried about that beefed up fuel pump. You are running rich and have a larger than stock fuel pump, could be part of the problem.

I would say to increase the idle, but I'm not sure how much you can do about it with the stock ecu. Lowering the fuel pressure would also probably work, but being able to do that also depends on your setup.

I'm wondering if your numbers are worse now with the snow because your CAT can't get up to temperature, what with all the snow and water and **** hitting it whenever your drive around. You might have some luck if you wrap the cat with some fiberglass or something to insulate it and get some heat into it. Would have to look like a decently professional/OEM type install though since they always look under the car at the CAT.

 

put the emanage back in and tune the car on 100% alcohol. It should burn out their test equipment.

 

just give him a wink, the secret handshake, and slip him a 20!

 

works wonders

 

your timing is to retarted bring it back to stock retarted timing will bring your hc's up at idle what was your o2 sat at or is everything else correct?

 

If you haven't already tried this you should. Worst the guy can say is no....or GTFO.

Vash-

 

$20?!? In Ca staged smogs are going for $250+