Ive done searches but haven't found what I need....

I bought a 92 hatch with a 95 USDM B18C1 (GSR) motor. The guy I bought it from said after he did the swap, he took it to get the emissions done in Maryland and failed. It came up "diluted sample". They told him to go drive around for a while and warm up the cat. After testing it again he got the same thing. So he just gave up and gutted the cat, never getting emissions done. The cat had about 150k miles on it.

I live in Virginia and need to pass VA emissions test. Im not too worried about passing the visual test, but I am concerned about passing the sniffer test. If you fail in VA, you must spend either $450 or $600 (not sure) to get a waiver.

So Im wondering what I should do to pass. Currently the car has a gutted cat, so Im wondering if I buy a carsound cat, will this work ok? Second, the car has an adjustable fuel pressure regulator, what psi should i have the fuel rail at?

Has anyone ever heard of a "diluted sample"? What does this mean? And what can I do?

thanks all

Scott

 

This website is from Connecticut, but it probably explains the same thing:

"A sample dilution rejection will be issued to motorists whose vehicle emissions cannot be properly tested because too much air is present within the exhaust sample.

The emissions testing equipment automatically determines if exhaust gases are being diluted before and during every test. It does this by verifying that enough combustion byproduct, carbon dioxide (CO2), is present in the exhaust gases. If there is not enough CO2 present, the computer will not allow the test to proceed and the vehicle will be rejected."

http://www.ctemissions.com/expect-dilution.html

What's the full exhaust setup like? What kind of header, what diameter pipes, etc.

Assuming you have a properly functioning cat and no exhaust leaks you should be able to pass no problem. Obviously a gutted cat won't work.

 

thanks for that info, now i know more about what im dealing with.

the exhaust is a little funky. I think when the previous owner went to test the car the exhaust had some kind of 2 piece header, then a flange where it bolted to the cat, then the cat welded to a 2.5" section that ended at a flange about 4 feet before the muffler. then for some reason at the flange, the pipe dia. goes to an almost stock looking size (like 1.75") until it reaches a dynomax muffler.

the previous owner told me that he had to replace the gasket on the 2 piece header a few times and ended up just getting a 1 piece obx header. do you think there may have been a leak at the header causing air to get in?

and finally, can i buy a carsound cat and pass emissions?

thanks a lot. im hoping i can pass this thing without emptying my bank account on a waiver.

 

It amazes me the weird, retarded solutions to having an exhaust that people dream up. Sounds like the guy really wanted a 2.5" header, but then used the stock exhaust pipes welded up to an aftermarket muffler. That's just dumb.

You could get a universal Carsound cat and have a muffler shop fab it up to work with the current system. It'd pass no problem as long as there are no leaks, but you would still have the same screwy setup which you dumped more money into.

Part of me feels like you should junk the whole exhaust setup due to high levels of crappyness and start over; although if that's not something which is affordable to you then I guess you're stuck with just making the current wacky setup legal.

 

that was pretty funny. yeah, the exhaust setup makes no sense. why would a guy leave a 4' section of stock exhaust?

but rather than buying a whole new catback, i was thinking about replacing that stock 4' section of pipe (between the flange and the muffler) with another 2.5" section. That way, the whole catback exhaust will be 2.5" at that point, and i can keep the dynomax muffler. i like the sound of the exhaust right now because it is completely low key, and does not have that rice-boy coffee-can attracting-cops sound.

is it best to just get a universal carsound cat and have a shop fabricate the flanges and o2 sensor bung? i was going to have a shop do that along with making a new 4' section with 2.5" pipe. and the NEW OBX header is good. do you think i should get a whole new catback instead? even if i got a new catback, i would still have to get the carsound cat separately anyway right?. and i dont want to spend a lot.

well, do you think it was the exhaust causing the "sample diluted" problem from what you've read?

 

i'd take it to the shop and have them fab up an ass-end 2.5" pipe to run to the muffler (it is a 2.5" inlet muffler, right?), weld in a cat and o2 bung, and call it a day for now. Have them look at all the flanges and gaskets to make sure there are no major leaks too. That should get you through the sniffer test, and if you feel like upgrading, you can do that later and save some money for now.

 

I don't think there is such a thing as "diluted sample" in VA. I've had a couple cars E-tested with exhaust leaks and the testers didn't really care.

Install a new cat and seal all exhaust leaks. It should pass from there.

 

Hrm, the 99-00 D16Y8 engines have air injection for emissions purposes. I know other makes/models do also. I wonder how this is accounted for.

Is your EGR system bypassed, maybe hook that back up again?

-PHiZ

 

They have an airpump?

Are you sure a '95 B18C1 has an EGR?

 

the 99-00 (OBD2B) D16Y8 have an air injection before the combustion chamber. I think when I've heard the term air-pump it is after the combustion chamber, it aids air to help the catalytic convertor's chemical reaction.

No matter what, this is all more information than a person should reasonably have to know to pass emissions.

You know there was just a thread where I said the motors had EGR, and I got my ass handed to me, as it was PCV fume recovery (diagram under your hood, charcoal cannister, et al.) However, there is a device called Evaporative Purge Control Solenoid, which is tied into emissions somehow too.

EGR:
http://www.honda.co.uk/owner/CivicManual/pdf/11-104.pdf

I've never seen that box under hood, so I'm going to go ahead and say USDM cars don't have it

Evaporative Emissions Control:
http://www.honda.co.uk/owner/CivicManual/pdf/11-110.pdf

Evaporative Emission Two Way Valve:
http://www.honda.co.uk/owner/CivicManual/pdf/11-113.pdf

:shrug:

Good luck.
-PHiZ

There are tuning guidlines for reducing emissions, like "reduce combustion temps, NOX levels go up" shit like that, I'm not familiar with them, I tune for power, not emissions... Usually if you have a cat, you're ok...