I went and got my 95 Civic EX inspected today and Passed everything but the emissions test. Basically i failed for too much NOx (Nitrogen Oxides).

It says the standard for my car is: 1088
It recorded a "score" of: 2509

The thing is i have an OBDII LS motor w/ a OBDI P75 ECU in this car. And, all emissions equipment is hooked up also.

Anybody know how i could get this down to a more acceptable level? Or what parts of the emissions system i should look into "fixing"?

Any help is appreciated.......

 

Simple, call a smog shop and ask them......don't know here.

Spade, who will have a custom B pipe with 4 cats for smog.

 

maybe you need to update your ECU to be OBDII compliant? is your cat working?

 

Well i just looked some info up on the net about Jersey Vehicle Inspections and found this:

"Your vehicle is judged only by the standards of the year it was built, with an allowance for wear and tear."

Would this mean that they are testing my car as if it has a D16 in it , or would there just be a set level (ie. the 1088 posted as the standard reading) for all cars of this year and mileage.......?

 

probably comparing to a d16

 

Compaired to the D16 but, you still have a lot more than what a B18 should put out.

only 200cc more displacement and really bad emissions.

 

Well all the others were below what they should be:

Hydrocarbons were 129, Standard is 141
CO% was .55, Standard is .79

Just the NOx was about double what it should be. Damn Jersey, this is the first time i went through this "new" test. The old test did'nt measure NOx........

 

What causes high NOx?

 

That's what i want to know. Which part of the emissions system causes it , So i know what to fix? Hopefully somebody will know.......

Edit- I should say which part of the system lessens it (NOx).....


[Modified by JV, 6:02 PM 6/28/2002]

 

I cannot get on the phone right now but, if you call a smog place by you and tell them you have high NOx, they will tell you what it might be.

 

Unfortunetly, i asked the guy who did the test and he said " The only thing i can do is give you a list of places that are qualified to fix it".
Which means that they are probably "in" with the "recommended" service stations to make some more $ off us tax payers (As if they did'nt take enough installing these new test facilities). God i hate Jersey sometimes.......

 

I was thinking the same thing only using 2 cats. Basically use a test pipe in place of the second cat until it's smog time. We just got tougher tests here in TX so I might have to do something. Problem is, I don't know if it will work.

 

Just make sure the vehicle is warmed up.....I.E. drive around for a while before getting smogged then while waiting leave the vehicle running.

 

Would maybe some kind of AFC help?

 

Hmmmm, The car was sitting for about an hour before it got tested. Maybe this is the problem????

 

well i had the same problem with my 98 civic dx, i had a completly stock internals, just clutch, flywheel, ignition, header, intake, exhaust, fuel rail, adj. fuel pressure regulator......it passed all the test except for the idle test i had about 300% over legal limit for HC (Hydro Carbon)

wel played with the fuel pressure to try and get it to go down, and we did but it was still about 50% over limit, so we finagled alittle more and got it to pass, but one thing the mechanics and i thought about was the fact that i have an aftermarket cat in the car because of the header, so on a hondas then tend to run so well that the cat cools off to quickly during idel so you have to heat them up pretty good in order for it to clean up, so thats what we did......im not sure if any of this helps but this was my recent experience

 

I DON'T have a clue
but then I took my B20vetc I threw In a stock 95 ex (P28)
and it passed eazy. Your car has to pass the standard for year and motor it was biuld with!

Is you computer stock or chiped? I bet this is the problem

 

Your car was sitting for an hour not running?? Yes, that would definitly be a problem. Your Cat has to be fully heated up to be effective, and it does take a few minutes to reach operating temperature.

 

It is a stock P75. The whole swap is bonestock.....

The only mod i have planned for it, is a custom turbo setup. Which i'm starting to doubt would ever pass inspection.....lol

The only thing i can think of is the cat not being "Hot" enough. My exhaust consists of a 2.25" "High Flo" cat with custom piping to an ES oval. Could the catalytic converters sizing have anything to do with it ......? Or should i just fess up to DMV that it is swapped?

Nobody in my area has a "Hybrid", so i have nothing to go by as far as other peoples experiences with swaps and DMV around here.......

 

I'm a state inspector in TX and for the last two years we've done a 2 spd idle test. We finally had to go OBD2 testing on 96+ cars, and ASM (dyno) on 95 down, which includes a new gas (NO) for us to test. In the last two months on this test I've seen a lot of cars pass on the HC and CO levels, but fail on the NOx. Our test is 15mph and 25 mph test, with a 2mph window and an rpm window of 800-2500 for both parts of the test. I've noticed something. One car could pass the NO by forcing the rpms into the upper area of the rpm window. For example, one inspector might run 15 mph in 2nd gear (because he feels he needs to shift because the rpms are getting up there) and the rpm drops to 1100-1200 at 15mph. And the car would fail for NO levels. BUT if you run the motor in first gear, at 15 mph, you can keep the rpms around 2300-2500 (still within the window of the test) and NOx levels come down. Same thing applies to the 25mph test....run it in 2nd gear, not 3rd, to keep the rpms up, and NO will probably come down. So bottom line, maybe you can ask the inspector to keep the rpms up for the test (as long as he's not breaking the procedures of the test)

If anyone is interested, I'll post a list of state suggested items (in order) to troubleshoot for HC,CO, and NOx.

In my experience with HC and CO, HC levels we've been able to decrease by doing such things as oil changes, engine degreaser in the intake manifold, oil treatments (smoke-b-gone, motor honey). Sometimes it's just impossible to get a car to pass without a rebuild or head job. CO can be decreased by adjusting MAP sensors and changing air filters. We aren't an emissions shop or anything, but we deal with this all the time.

 

Thank you, This is the type of info i was looking for......

The test you perform in texas is just like the one in Jersey. If you could please post that list you were talking about, that would be great, Thanks.......

 

Still need help......

 

keep your car idling for like 20 minutes before you get tested.
you might want to clean out your intake mani and throttle body with carb cleaner the night before you go in. this helped a couple people i know pass.
the hella ghetto way is to dissolve mothballs in your gas tank. just like 3-4 for a quarter tank. i know some people that have done it, but i seriously don't trust it.

 

ok my mechanic and i were talking about it and came up with a few things

NOx are a byproduct of high combustion chamber temperatures, i.e. high compression pistons or turbo.

but since you do not have either(yet)

do this

1. retard yout timing to the maximum ALLOWABLE per your state for smog

2. make sure there are no vacuum leaks, vacuum can make the engine run lean and HOT, hot is what is increasing NOx

3. make sure the engine itself is not running hot, i.e. thermostat is good, fan is cycling, good radiator, blah blah

4. if worse comes to worse for fine tuning run slightly tighter vavle clearences, so it will slightly increasing the amount of unburned fuel, there by cooling the combustions, but this can cause problems in other areas of test i.e. HC, USE for the test, DO NOT RUN ALL THE TIME LIKE THAT, this is just for the test.

5. depending on the age and mileage of the motor you could run a top end cleaner. because alot of carbon deposits can actually raise the effective compresion ratio.

6. if nothing else works, run a water injection system, or light it on fire and call it a day

7. or find a import friendly smog station, but shhhhhh dont tell anyone

 

Thanks for all the advice guys. I'll keep you posted on how it goes........


[Modified by JV, 10:05 PM 7/2/2002]