DA-B16

Hello all, in a couple of days I will be going in for my third ref appointment. I have an OBD1 JDM (P72) B18c in a 93 integra and, as the title says, it wont pass the sniffer test. A quick rundown on my setup: I have the CARB legal Skunk2 IM, stock exhaust (including the manifold), stock intake plumbing with a K&N drop in, USDM GSR ECU, and all of the correct wiring and vacuum lines hooked up, always use 91. Here's the numbers from the first test

15 mph
CO2=14.2; O2=0.6; HC Max=89, Meas=151; CO Max=0.53, Meas=0.64; NO Max=708, Meas=2627 GROSS POLLUTER
25 mph
CO2=15.0; O2=0.1; HC Max=54, Meas=69; CO Max=0.51, Meas=0.16; NO Max=746, Meas=716 Fail

OK so the first test the 15 mph failed miserably. The NOx made me a gross polluter! So after this I did a major tune up. I changed the plugs, oil, checked (and cleaned)the wires/cap/rotor (all recently changed), new cat, new NTK O2 sensor, new pcv valve/hoses and block breather, new fuel filter, ran seafoam on one tank and Lucas fuel system cleaner on another, cleaned the TB and IACV, new thermostat, and used a bottle of HEET in the fuel I used on the second test, and here are the results from all this work:

15mph
CO2=14.8; O2=0.3; HC Max=89, Meas=128; CO Max 0.53, Meas=0.34; NO Max=708, Meas=2731! GROSS POLLUTER
25 mph
CO2=15.2; O2=0.0; HC Max=54, Meas=45; CO Max=0.51, Meas=0.11; NO Max=746, Meas=737 Pass

So I'm getting a little closer, I actually passed the 25 mph test! But now what!? I Know that high combustion temps/ compression yield higher NOx numbers but timing is right at 16 degrees and with all of this new crap I figure it should pass! I have a couple theories as to what the problem is.
1. I didn't wire something correctly that wouldn't throw a code if it were bad (i.e. purge control solenoid)
2. Bad coolant temp sensor? My fan never kicks on and my system has to relieve pressure often (but never overheats/goes passed half way mark on gauge)
3. Vacuum leak somewhere? I sprayed carb cleaner anywhere and everywhere there could be a vacuum leak and there was no change in idle speed. There is however a slight surge when I hold the throttle at any rpm. My buddy brought home a smoker from his shop and we didn't see anything (car was still hot though which sometimes makes it hard to see the smoke)
4. Bad or going bad sensor? Maybe a bad MAP sensor or TPS, IAT, etc?

Sorry this is so lengthy, if you made it this far I appreciate your time. I'm just really in a bind. The DMV said they wont give me anymore extensions and I have a month left. Not to mention I'm kinda broke, so I can't afford to blindly throw money at new sensors and crap that don't need to be changed. If you have any input it would be greatly appreciated.
Thanks,
Eric

DA-B16

I forgot to add to theory number 4. I have an intermittent rough start. By that I mean once every one to two weeks, when I try to start my car, I will have to crank it for a while (up to about 5 seconds) and/or followd by a stumbling start. the stumble only lasts for the first seconds of the initial start up. I had a similar problem in my old teg. It had a B16 and did the same thing (more frequently and ran crappy) for months without throwing a code. Finally it thew the crank position sensor code and I just replaced the distrubutor, which in turn fixed the problem. I figure that the obd0 system is a bit more lax than the obd1 which is why it took months to recognize the problem? I just wish my current setup would throw some sort of a code to give me a smoking gun!

Ventolin

Failed my inspection with numbers similar to yours.

Retard your timing slightly, I retarded mine around 2-3 degrees. I then ran my car down until it was almost empty, then put 3-4 bottles of ISO Heet in the car. Ran it for awhile, it ran shitty and smelled like crap.

Took it to the inspection again, the lady took one look at the car struggling to idle, fuming all kinds of nasty out the tailpipe, laughed and told me not to waste my money and fix it first. I told her to test it anyways.

The look of shock when I blew the cleanest reading she'd seen in months said it all.

Ventolin

NOX can be caused by alot of things, high cylinders temps and detonation. Flush your coolant, too, maybe add a tiny drop of dish soap (or redline water wetter if you want to waste $10)

DA-B16

Did she check your timing? The ref checks the timing and I don't think he will pass anything other than 16 degrees. I did use a (only one) bottle of HEET on the last test but got even worse NOx numbers. I don't know, there has to be something not functioning or interfacing correctly. I know that high compression and combustion temps raise NOx, but the ratio isn't that much higher than the USDM variant. As long as EVERYTHING is hooked up and working properly the was it was designed to it should pass. The ref said himself that he has passed countless JDM engines with flying colors

kp

Move up north brother! I live in Ontario, Canada and when I swap my D15 (94 Civic CX) for my B16, all I have to do is declare it has an engine swap and they consider it a "hot rod" test. It doesn't matter what the emissions readings are, Guarenteed pass!

deadsquid

I had the same problem and did almost everything you did to pass. I finally passed and I believe it was because I used an OEM USDM cat off a GSR. It has to be an usdm not jdm because the jdm one is smaller. For some reason it filtered out more nox and I passed and got my bar sticker. Hoped this helped, good luck.

DA-B16

I am more and more tempted every day! Problem is I HATE the cold. Shoot if I were to move 30 min south I wouldn't have to worry about it either! Then again I would have to worry about drug cartels and corrupt federales. Almost worth it...

DA-B16

It's a brand new universal fit applicable to a USDM GSR (according to the people I bought it from). I am really starting to think that a sensor is going bad and/or getting a bad reading and in turn causing the ecu to lean out the mixture. Those numbers are way too high for a Honda engine with everything working properly. Higher compression or not. I tried to get around to tearing crap apart yesterday but I have yet to find the time. Gonna get crackin on testing all of the sensors I can think of tomorrow.

stealth50k

Make sure your tps sensor is calibrated right with a meter. If it isn't calibrated right then just a little throttle body open can mean full open in the ecu. It could be malfunctioning also. Just gotta check. You can try some high octane gas on the next test also. Make sure that cat is heated up also. When your signing papers and all that make sure the car is running the whole time because if the cat goes cold its game over. Gotta keep it hot

mini-cRx

i got a k eg with same problem i put high octane in tank and booster but heard this is worse actually ? also i got cat on there but not sure if working. i heard low octane helps

mini-cRx

one thing i did was lay my intake over the front bumper with fan right on it and it went down 600 nox haha

Ventolin

High Nox is almost always caused by two things. Hot spots in the cylinder, or running lean.

Look it up and see how much room you have to work with, usually you have about 2 degrees of variance that is acceptable in your timing.

High cylinder temperatures could be caused by lots of things. Maybe you have air in your coolant or something, that can cause hot spots in your cylinders and give high Nox. You may have an oxygen sensor going bad or something like that. Maybe it has to do with running the USDM ECU on the JDM motor, which has slightly higher compression? Maybe thats why its running lean?

Either way, retarding your timing as much as you're allowed to will help tremendously. The ISO heet will work, too, but you've got to get a good percentage of it, enough to really make a difference.

These are just ways to cover up the problem, but eventually you'll want to properly diagnose whatever the problem is and correct it.

DA-B16

Exactly right about covering up a problem. I know of a couple people that I could give 200 bucks to that would "smog" my car but I want it running the way Honda intendid it to run (besides being legit). I just finished replacing the fan switch which was bad and I'm sure that will help keep overall temps down (now that the fan actually kicks on), checked a few other sensors (keep getting a funny reading from the MAP, but I think my multimeter is taking a crap), and added a bottle of water wetter to the cooling system (and bled it). I'm gonna recheck my new O2 sensor and do a more thorough check on the MAP sensor tomorrow. Thanks again for your help everyone.

Extent

When I did my first test I had an AEM short ram, Edelbrock header and a Random Technologies cat, all brand new. I failed on high NOx (~1k) and modified cat (dispite it's Carb EO# :/ he didn't like the placement of the O2 sensor)

On his recommendation I replaced the RT with a new OEM cat ($$ ouch) and no other changes. Passed my second test with almost 0 NOx. No additives or funny tricks, just a good preheat before going to the test.

No idea how related that could be to your problem, but I've certainly gained a healthy suspicion of aftermarket cats, at least when it comes to passing CA Smog.

--edit--
timing allowance is +- 2 degrees

DA-B16

Yeah I'm kinda in denial about my brand new cat's efficiency. If I fail this test I guess I gotta face the music and buy an oem unit. I can't afford a dealership oem cat, but I might be able to swing a Walker or some other highly reguarded oem cat. Did you actually get a factory replacement? They want like $700 on hondapartsunlimited! And thats cheaper than the dealership.

Extent

Yup, I got mine straight from Del Ray Acura online, I knew that an OE cat would work and didn't want to potentially waste any more money on another aftermarket one, even though they were so much cheaper.

I had done a full tune up before (cap, rotor + everything else) and a valve job, and my motor was super clean and in great shape. At worst I got half of what your test is showing, so I don't really know if it would solve all your problem, it just made a huge difference in my situation.

DA-B16

Ay guey! This is gonna be painfull I can tell. Well I go in for another test on tue. and I'm gonna borrow a (known working) MAP sensor from my buddy because mine is giving me wierd signals (old multimeter though). They're just a pain to test so I'll just eliminate the BS and use his. Thanks for the input Extent

DA-B16

I was pokin around with a new (borrowed) multimeter today and I got 4.5 volts going to the MAP sensor when it calls for 5 (ignition on not running). I'm not very savy when it comes to electrical components but would that be cause for concern?

DA-B16

Got another new cat but this one was much bigger and more expensive (more precious metals) and it has a CARB EO#. This one worked! But barely... I'm sure I could bring the numbers down a bit (NOx still high but within legal limits) but thats for another day. Thanks for the help guys

sleepgsr

Rubbish. You still have to pass a certain standard. There is no guaranteed pass unless your car is older than an 88.

Tensa_Zangetsu

wait so u passed after u got a new cat? so that means its the aftermarket cat that u had before that caused u to fail? cus i just got me a new magnaflow cat and heres my reading.

25/25 Test:

Reading: Allowed:
HC ppm 40 160
CO % 0.00 0.90
NOx ppm 2282 1179

50/15 Test:

Reading: Allowed:
HC ppm 45 166
CO % 0.00 0.93
NOx ppm 3187 1304

racebum

two thoughts.

#1 use a jdm OEM cat. i wonder if a 97 spec type r header would fly since they look so similar to the GSR manifold. it would allow a 2.5" cat as well

#2 with the single stage manifold on a stockish gsr i had a lean condition that was fixed with a few psi bump in fuel pressure. my long fuel trim was like +9 before i increased pressure.