How to get my non-CA VX to pass CA emissions test?

[RobbieVX]

So i bought a very very clean 94 civic vx from an original owner in arizona about 3 months ago. I know that the car is the 49-state "lean burn" version, but i was under the impression that any 49-state car could be brought into CA as a used car (7500 mi or more), they just couldnt be sold as new cars. I figured that the cars coming from out of state would only have to meet federal smog requirements and not state. Yesterday i took the car to get smogged and it failed badly, but im almost positive that there is nothing mechanically wrong, i think its just the lean-burn mode putting out the excess of Nox. It failed at the 15mph test where max allowable Nox is 700 something and the reading was over 2000, im pretty sure it passed or got close to passing the 25mph test. Was i wrong about bringing a 49-state car into CA? is there anything i can do to get the car to run temperalirly clean for the smog test?

thank you in advance.

[Matt Timion]

Originally Posted by RobbieVX

So i bought a very very clean 94 civic vx from an original owner in arizona about 3 months ago. I know that the car is the 49-state "lean burn" version, but i was under the impression that any 49-state car could be brought into CA as a used car (7500 mi or more), they just couldnt be sold as new cars. I figured that the cars coming from out of state would only have to meet federal smog requirements and not state. Yesterday i took the car to get smogged and it failed badly, but im almost positive that there is nothing mechanically wrong, i think its just the lean-burn mode putting out the excess of Nox. It failed at the 15mph test where max allowable Nox is 700 something and the reading was over 2000, im pretty sure it passed or got close to passing the 25mph test. Was i wrong about bringing a 49-state car into CA? is there anything i can do to get the car to run temperalirly clean for the smog test?

thank you in advance.

Hey Robbie.

First of all, your 49-state VX SHOULD pass CA emissions. This is the first time I've heard of it being an issue, so I doubt it's the fact that it's a non-CA car.

You might want to check a few things to ensure that it's up to par, like the oxygen sensor, the spark plugs, and the spark plug wires. Check the distributor cap/rotor as well.

A bad oxygen sensor will definately affect your emissions. My wife's CRX went from horrible to super clean after changing her oxygen sensor (just be sure to reset the ECU after changing it). If youare unsure when it was last changed, I woudl recommend changing it. YOu can get a brand new five wire oxygen sensor on ebay for $170 (compared to Honda who charges over $300).

The VX has special spark plugs and spark plug wires which higher resistance. If the wrong plugs/wires are installed (very common) then the emissions will be affected as well. I would also recommend gapping your spark plugs to the proper width. It makes a big difference. Do NOT buy the pre-gapped plugs.

If you have the money, I would recommend getting the parts from a honda dealership. They will know EXACTLY what you need. Autozone will usually give you a part that will work, but not one that is made specifically for the VX.

Lastly, the vx has a hotter thermostat. if you are having excessive emissions, you might want to put a cooler thermostat in the engine. It will affect your MPG (might not hit lean burn) but the engine will run cooler and not produce the NOx.

lastly, check the internet for causes of a high NOx level. It's usually sometihng to do with the temperature if I remember correctly. O2 sensor is a huge culprit.

[RobbieVX]

thanks for the quick reply matt. i think i automatically assumed that since theses cars put out more Nox, and that it failed because it put out too much NOX, that it was simply b/c it was from out of state. So in theory, a 49-state VX should still put out less Nox than the CA max? i thought the reason why they werent sold in CA was because of the high Nox levels, but this still must be under the CA max of 700 something, right?

anyone have any NOX readings from their 49-state VX that they could compare?

has anyone ever smogged one of these 49-state VXs in CA?

oh, and the smog tech tried telling me that the CAT was probably bad, and he could weld me in another one (instead of charging me the $700 for an OEM replacement) further down the exhaust system and that 99% it would pass. Im guessing most of this is BS, but are cats known to go bad?

[GasSavers_Ryland]

Originally Posted by Matt Timion

Lastly, the vx has a hotter thermostat. if you are having excessive emissions, you might want to put a cooler thermostat in the engine. It will affect your MPG (might not hit lean burn) but the engine will run cooler and not produce the NOx.

a hotter thermostate will defently drive up NOx leavles, and when I bought a new 49 state emition thermostate from the honda dealer, it was a 180F one, I wasn't able to find a 195F thermostate at any of the auto parts stores either, the honda thermostate was also of a much higher quality, heavy stainless steel with solid rubber seals, insted of flimsy stamped tin and brass seals.

[Gary Palmer]

I think that your going to probably find that you have to address the cat, one way or another. I'm pretty sure that with the level of NOX you've got, combined with doing all of the other things that people have suggested, you should be able to pass.

I think that their are some funky things with the Nox and the cat, because if your sitting down on the edge, a new cat will clean things up, but the reason CA requires you to get it smogged every two years, after it is over 5 years, I think, is that an older engines emissions can kill a cat fairly quickly and that way they have that base sort of covered.

If you can get the cat done for any kind of reasonable figure, I'd just do that, as well as all of the other things which have been suggested. The cost for retesting, if it doesn't pass again, just makes all of these other things more cost effective than fiddeling with it, IMO

[RobbieVX]

here are my numbers:
15mph
co2-14.0
o2-0.7
hc- max-92 meas- 115
co- max- .55 meas-.5
no- max-716 meas- 2013

25mph
co2-9.4
o2-7.2
hc- max- 57 meas- 187
co- max- .54 meas- .08
no- max- 764 meas- 347

does this suggest a bad o2 sensor? im thinking i need to check timing, replace cap/rotor/wires/plugs, get new o2 sensor, put high octane gas in before test? , weld in secondary cat after header?

[omgwtfbyobbq]

Depending on how much you pay for the test I'd do exactly what you said, except just replace the factory cat. No need to drop in a second cat with a small engine like that. And make sure it doesn't go into lean burn during the test... Not sure how, but there's probably some way to accomplish this.

[Matt Timion]

Originally Posted by RobbieVX

does this suggest a bad o2 sensor? im thinking i need to check timing, replace cap/rotor/wires/plugs, get new o2 sensor, put high octane gas in before test? , weld in secondary cat after header?

I really doubt that higher octane gas is going to help. You're better off using one of those engine cleaners that guarantee you to pass emissions. Even those, IMHO, are silly.

I would get new plugs and wires and gap the plugs properly. I would then see if the oxygen sensor has ever been replaced. It's unfortunate that it's such an expensive item for the VX, but that's just the way it is.

I'm wondering if you can just get a CA-VX ECU and swap ECUs for the testing to avoid lean burn.

[omgwtfbyobbq]

I should also add that worse case situation, if the cost goes past $450 at a licensed Smog Check station, you get a one time only two year smog waiver. There are also gray methods of getting the car done...

[GasSavers_Ryland]

OEM Cat for the VX is $435, and is held in by 7 studs, I didn't find it to be that hard just to unbolt my cat, and look at it, to tell if it was any good, it should be clean, white, without any blockage, or chunks missing, on the VX the cat bolts right to the exaust manifold to make sure it gets hot enough, installing one latter in the exaust system might not be as affective as it wouldn't get as hot as fast.