Boomer111

Guys,

You are not seeing something...

At the smog test, they connect to your PCM via the OBD2 port and read these things (using Mode $09):
- CAL ID for each segment,
- CVN for each segment,
- VIN of your vehicle,

they then use the VIN to look up a database containing valid CAL ID and CVN values for your VIN (this is already in place for 2005+ cars);

the CVN's are like checksums; when tuning software writes to the PCM, the tuning software calculates what the CVN should be for each segment and writes it to the PCM; when you turn on the key, the PCM performs the same CVN calculation and expects to arrive at the same values;

if you have significant engine mods, you would have had your PCM tuned, which means the CVN for the engine segment now differs from original...

if you deleted codes, then the engine diagnostic segment CVN differs...

if you had your auto trans tuned, then the trans segment CVN differs...

if you changed your ring/pinion ratio, then your speedo segment CVN differs...

if you changed your fan on/off temperatures, then your system segment CVN differs...

[ if GM reflashed your PCM for some reason or other, CARB will know about it (since the PCM is an emissions device), and the new CAL ID and CVN will end up in the database ]

if your car is a 2005+ they will definitely see the differences in CVN values, and they will fail you;

if your car is 2000-2005 they may still be able to pick up on these differences, even tho they didn't legislate for a database for cars prior to 2005; that doesn't mean they don't have a means of looking up and checking (they have had the ability to store the CAL ID and CVN values from all your previous smog tests, and they have the computing ability to detect differences, they just can't necessarily compare them to the OEM values);

in short, this is looking bad.

Copied from another source

I also noticed that I posted in the wrong section, it belongs in off topic.

ladder13

Waiting for Chuck.

VET4LES

You can delete a code and still pass. You just need to wait a week or two before the test. How else can you fix a problem and pass?

OnPoint

Boy, if we could just have more regulations the world would be grand, wouldn't it. . . . ?

cclive

Interesting info....thanks! Also, maybe Tech and Perf is the place for it.

Marc V.

Is that just for CA?

I think in NJ, as long as there are no codes and all monitors have run, you get a pass.

boraxman

/Scribed

S'vette

Or you find the guy that for an extra 20 will pas you.

cclive

Yes...just like everything would be better if we let an insurance company plug a monitor into the OBD port and leave it there to see exactly how we drive....

Boomer111

I have read that there are 22 other States that have adopted this already.