tbirdscwd

Does anybody know what parameters in the tune require changing to make a car with aftermarket cams pass a smog check in CA? They are custom ground blower cams (stage II for the sake of simplicity). I only have a couple weeks before this thing needs to pass inspection. I have custom tuning software which allows me to change whatever I want in the tune, I also have a wideband if that is necessary. Thanks guys, I hope there are at least a couple guys on here that can help.

Please don't respond if you are from another state and don't know what is involved with a smog check HERE. Comments about check engine lights, throwing codes, rear 02s, and how in the county you live, all they do is plug in the OBDII and check for codes are not needed.

Derf00

I lived in cali for about 20 years. There is no easy way to "fool" the CA smog check. THey run the scanner and put it on a dyno with a tailpipe sniffer. Every car has an acceptable range for NoX, CO, Hydrocarbons, and I forget what else. If your car falls out of range on any of the tests then you fail.

Depending on the condition of your cats, the type of cam you have, and any other minor engine problems that by themselves would not cause you to fail, you may or may not be able to tune the car to pass. It's not a simple, oh lets change this parameter here and viola you pass. Run too lean and you'll fall out of range, run too rich and you'll fall out of range.

Do you know if your CAMS are CARB certified?

StriderTacticaL

The best and easiest way for you to pass smog is to find someone to knows people who will pass you with a couple of Benjamins.

Ehmark

Last i checked changing cams was illegal so no carb number.what you can do is have your tuner disable all codes they will show up as n/a on the sog sheet they smog guy wont know whats going on and will have to pass you. Then you need to make sure you have cat that are legal. Go to a smog place and ask for a practice test, practice test will keep you from officially failing, if it passes the sniffer your good to go. If you dont pass the sniffer then google for tricks to water down the gas with rubbing alcohal or other things. If you can reduce the hc concentration of the gas then you will lower the un burnt hc of the exhaust. Running your car like that for too long is not good for it so as soon as you pass top off the tank with fresh gas. One last trick make sure to heat the cats as much as possible before test, hell you could even add cats to pass.

MU71L4710N

stock H pipe on the NPI mustangs had 6 cats. you'd be hard pressed to fail with one of those on there.

cliffyk

The problem will be that at idle the extended overlap of the hot cams will cause quite a bit of the intake charge to get through to the exhaust--the unburned fuel will decompose a bit in the heat of the exhaust gas and drive the HC content way up.

I am not aware of anything in the tune that will, or even could, prevent this. Keep the idle speed up as high as you can, although I believe they will fail you for too high an idel as well.

A shiny new pair of cats might help--IDK...

Ehmark

Research the idea of running rubing acohal in gas or other additives.