This was a post I made a few years ago on the forum after I was put through the ringer by the Ca. Emissions Nazis. I thought some of you may find it useful.
DISCLAIMER - The opinions expressed below are just that, OPINIONS, and are worth every penny you paid for them.
Use any of the included information at your own descretion and risk.
Through a long and painful process this is what I have learned about California emissions testing and a few things to do that will help get a car certified.
First here is the link to the California Air Resouce Board - (C.A.R.B.)
(I have another name for them but I know this is an all ages site - I will leave it up to your imaginations)
NOTE - This is a collection of all the rules & regulations not just laws concerning automobiles.
This site although geared to engine swaps has the best description of the smog inspection process that one would go through if you have after market parts installed.
This site is the database of approved after market parts and their associated Executive Order numbers.
Executive Orders are issued for aftermarket parts that manufacturers have submitted for testing and that have been proven NOT to increase the emissions. Any aftermarket parts used in CA have to have a EO number or you will fail the inspection. This is where you find what parts you can use on your vehicle when building or modifying your car.
This site is a listing of emissions standards in use for CA at this time.
This is C.A.R.B.'s Smog Faq...simple but slightly useful.
This site allows you to check the smog test history for a particular vehicle using either the VIN or the license plate number. Handy if you are looking to purchase a used car. VIN lookup is usually best.
Personally I find it disturbing since it is another 'Big Brother' tactic of data collection, but handy none the less.
For those of you that still have not gotten your fill of laws this site will give you access to current California air pollution control laws.
Now for the list of things I found that helped get the car into the acceptable emissions range.
1. Most important make sure that the vehicle has no mechanical problems.
2. Change the oil before the smog check. The PCV system of your vehicle is designed to allow your engine to breath fumes located in oil compartments (oil pan, ect.). The fumes are then burned through the combustion process. Contaminated oils are high in Hydrocarbons and will present a rich mixture to the engine chambers(too much fuel). If the oil in your engine is contaminated, it may very well cause your vehicle to fail the inspection.
3. Right before testing make sure you drive long enough for the car to reach full operating temperature.
4. Use a good fuel additive. I have used "Guaranteed to Pass Emissions Test Formula (12 oz.)" for years. In my experience it will reduce the tested emissions levels by about 10 - 15%. If your vehicle is borderline failing this
will do the trick. You need to put the additive in the tank and then fill the tank. Drive the car over a period of days until you empty the tank. Then refill tank and go straight to the testing station.
You can obtain Guaranteed to Pass here >> http://www.autobarn.net/ch05063.html
or from most major parts stores.
There are other good additives such as Blue Sky and PuraGas Emissions Test - Fuel catalyst (fuel additive) for gasoline.
I have no personal experience with either of these products, only the rantings and ravings of my friends.
5. Returned several areas of PCM programming back to factory settings.
(You did make a copy of these before tuning, didn't you??)
I have documented the settings and may be convinced to share these if asked politely.
I also have a original spec factory programming in LT1-edit file format that I can share.
%Power Enrichment vs RPM adjustments
KNOCK RETARD MAX LIMIT vs MAP, non-PE - changes only in the 95 & 100 Kpa ranges - doubt this came into play during testing.
MAF vs Frequency calibration
KNOCK RETARD MAX LIMIT vs RPM in PE - changes only in 4000 rpm and above - again doubt this came into play during testing.
Spk Adv 400-4000 RPM - changes in the 1800 rpm and above ranges.
These changes brought all areas to extremely low readings, except the NO readings. NO was still too high to pass.
The final change was to the temperature the cooling fans turned on.
This snapped the NO readings to acceptable levels.
Instead of the normal 178 / 178 settings which keep the engine temp in the 180 - 185 area I set them to 226 / 235.
This allowed the engine temp to reach an average of 220 during idle and dyno testing.
A catalytic converter works best when it is hot.
Good luck and good testing.
Questions ???? Just ask.
As always I am open to giving my opinion to anyone who will listen.