CA emissions fail

[llilibel03]

HI. I've got a 85 with a tiico conversion done in 2003. The tiico has 30,000 miles.

I failed smog. 15mph NOx was high.

A couple suggestions i've gotten were to put denatured alcohol into the gas and to run the van on the highway for at least 20 minute to heat up the cat convertor.

My research however sayas the high NOx is due to a lean mixture which causes high temps which lead to NO. This is what was said on one site-

It (alcohol) should / will have minimal impact on NOx. NOx occurs from too lean an air/fuel mixture. When there’s too much oxygen. You can think of it as the alcohol makes the fuel burn hotter… and that’s the opposite of what you want when your NOx number is high.



Also if NOx is caused by high temps wouldn't running the car on the freeway to get the cat convertor hot increase engine temp and thus NO?

All I've done is cleaned my KN air filter and changed the spark plugs. Also plan to momentarily over inflate my tires for what that's worth.

Anything else I can do?
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87 syncro tintop
90 gl tin top
85 westy 2.0 tiico automatic (present)

[termuehlen]

Check your exhaust system for any leaks between the engine and the Oxygen Sensor. This was the cause of my high NOx emissions failure a few years ago.
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1988 Westfalia automatic Subaru OBD1
1986 syncro tintop wbx

[sjbartnik]

Does that engine have EGR (exhaust gas recirculation)?

EGR's purpose is to cut emissions of NOx by recirculating a little exhaust gas into the intake under certain conditions.

If your engine does have such a system, ensure it's functioning correctly and doesn't have any leaks (bad gaskets, rusted out pipes etc) as that would admit excess air into the intake manifold causing a lean mix.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[llilibel03]

No EGR.

Am I correct in assuming that running the car and getting it hot (the cat convertor) is not going to help reduce the NO levels?
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87 syncro tintop
90 gl tin top
85 westy 2.0 tiico automatic (present)

[sjbartnik]

Getting it nice and hot would tend to lower HC levels but not necessarily NOx levels. The catalytic converter is mostly there to reduce emission of unburned hydrocarbons, not NOx.

Check for vacuum leaks
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[davevickery]

I think he just needs a new CAT unless his engine has an EGR valve and it is stuck.

Adding alcohol to the gas could help a little with NOX because it burns cooler than gas. If you were close to passing, you could try that, but it won't make a huge difference by itself. Higher octane fuel helps too, but not that much. You probably just need a cat or o2 sensor. If you have a way to test your o2 sensor and see it cycling properly, then I think you will probably just have to replace your cat.

Here is my thread from when I had high NOX. https://www.thesamba.com/vw/forum/viewtopic.php?t=663025

Cliff Notes version: I put in a Cali CAT and NOX dropped from 5.8 NO to 0.30. My recent 2 year later retest wasn't as impressive but I still passed easily.

[llilibel03]

[davevickery]

[jberger]

Check your o2 voltage while running.. it should bounce constantly between 0 and 1 volt. If it’s hovering around a narrow band... that’s your issue. Just went through this with my mk2 8v

J

[Abscate]

You want the cat as hot as possible , which helps conversion of CO, HC, and NOx. The combustion temperature at the 15 mph test won’t be impacted by a good hot run cycle before.

Try a hot run to a pretest place and see how it tests out.

Thanks for not killing children with a dirty car. It matters
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.ssS!

[912 outlaw]

Put some good chevron 91 octane in her and run her some hills to burn her out and get that cat hot. High octane gas will help with her running a little cooler.full tune wouldon't be bad with oil change too

[llilibel03]

Failed the retest.

Here's what I did- changed plugs, cleaned KN air filter, overinflated tires, ran the last 1/4 tank of gas with a double dose of sea foam, filled it up, ran it for another hour on the freeway and then took it in. Same result- failed 15mph NOx. A little better but still failed.

I looked at the PO's smog results. One thing I noticed is there was an "iginition. timing" number- 5 BTDC. My tests said "not applicable." Is the PO's number a retarded value? Could that be my winning ticket? Temporarily retarding the timing? Could that throw the other values off?

Since the other numbers are passing I'm kind of doubting the catalytic is the problem.

Also, while googling the issue it was said I could tell if it was running lean by looking at the O2 numbers. Mine was 0.0. PO's was 0.2


Finally, I was told on the tiico yahoo page that there is no EGR.
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87 syncro tintop
90 gl tin top
85 westy 2.0 tiico automatic (present)

[82westyrabbit]

Hi. We all keep guessing at why it is not passing the smog test. Of course cking the tune up is always first on the list. When you look at the spark plugs ck to see if they all look the same color. If one is a darker color then you might have a bad injector (which I doubt). If everything looks good there I would find someone that can hook it up to a computer (probably Ross tec) or a V.A.G. tool. At which point you will know that the various sensors work particularly the 02 sensor (probably the problem). If you get through to this point and have not found the problem then it’s probably the cat. Just replacing the cat may take care of the problem by covering up the real issue. Any way that’s how I would approach this problem. John

[davevickery]

[Abscate]

Post up the test report, let’s look at all the data.

Cover up name and address for pricacy of course,
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.ssS!

[ckissick]

Every time I've failed I've replaced the cat and passed. Simple.
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Charlie
1950 Beetle
1983 Westfalia
1989 syncro Tristar
1966 Porsche 912
1989 Beck Spyder
2007 GTI Fahrenheit

[llilibel03]

Passed.

I went to my old Audi guy. He retarded the timing 5 degrees and also put in different spark plugs that he said were "cooler" - Bosch W5DC.

He also told me he knows folks who put in the expensive California cat converter for the test and then swap it out for the 49 states one and only use the expensive one for the test. He said is some new Audis with two cats the cost of the CA ones can be $800.

He also mentioned that on the tiico there were no timing marks anywhere so he just made his own mark o the distributor.
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87 syncro tintop
90 gl tin top
85 westy 2.0 tiico automatic (present)

[tjet]

[82westyrabbit]

I glad you got through the smog test. The timing marks are on the crank pully on the timing belt end of the engine. To set the timing properly needs to be connected to a computer/scan tool. Now that you have passed smog test you probably want him to set the timing back where it was and the old heat range plugs in back in. It probably would be a good idea to scan the system every so often anyway. Happy driving. John

[llilibel03]