1FastBrick

iTrader: (16)

The calibration ID number has to match what was available from the factory or what has been authorized as a suitable replacement calibration from the OEM for that year, make, and model.

How ever the OEMs did not keep the best records as in some cases when you look on GM vehicles prior to 2006 it shows calibrations but no known check sum.

The C.A.R.B. smog program is going to look for things like Custom Operating Systems where the calibration number changes. Or like some aftermarket tuning equipment puts an extra character when it re flashes it's canned tune.

My understanding is that currently, it takes a snapshot from your vehicle's PCM/ECM of the calibration as well as the some other info like the VIN that is stored on the module.

It looks for the Readiness monitor status and probably when the last time the codes were cleared.

What I don't know is how they determine if a calibration is correct for your vehicle and if or when it fails you for it. Is it done on the spot or does someone review the information and look for anomalies?

I almost positive a COS operating system would fail or DSP 5 tune would fail right away.

But what if you flashed say a flex fuel operating system into a non flex fuel vehicle and they both happened to be the same year?

Or what if you put an 05 operating system in an 03 vehicle and corrected the Vin number.

Jeep_junkie

2000 and up cars are not sniffed at all - only visual and readiness monitor check. What fails aftermarket tunes is manipulation of the readiness monitors. Say for example the heated catalyst monitor, which won't set with long tube headers, is often programmed to not run, meaning it won't set a DTC, but it will always show as ready. The tech will reset the monitors so none of them should be set to ready when the let is turned back on. If any are ready, it's an automatic fail.

Jeep_junkie

My 2000 has a motor swap from a 2001. The vehicle was referred to Bureau of Automotive Repair and they certified the swap with a sticker noting the change in emissions equipment and the VIN. This was all done by the previous owner.

G Atsma

Okay, so what if all functions still work as designed, but ONLY the tune itself is changed?

1FastBrick

iTrader: (16)

Your 2000 what??? has a 2001 motor From????

1FastBrick

iTrader: (16)

They Can Not Reset the monitors during the testing process. If they do the test would automatically fail.

camarosam22

So out of curiosity if you have a 224 cam with 113 or 114 lsa, which is a pretty mild cam, and the tuner just tunes the timing and air/fuel mapping but leaves all the emission systems alone. This will not pass smog? I find this hard to believe. I'm not a guru at this smog stuff though.

G Atsma

The 224 might be a little too lumpy in the idle dept. A rough idle means sloppy firing at low RPM, which might set off a code or two (JUST speculating here).
I'm learning about this stuff too, being a fellow Californiano.

Jeep_junkie

Sorry I thought it was self explanatory. I was talking about the LS1 fbody in my signature. 2000 was also the last year for EGR. 2001 models got the !EGR LS6 intake.

Jeep_junkie

I believe they do this after they've done all their testing. Probably not even all techs do this.

joecar

I believe the test machine does this at the very end.

RB04Av

Easiest way to check the tune, is the checksum.

Common technique in ANY kind of programming... to identify the program, you just add up the binary value of every word in the program, and compare it to the "gold standard" whatever that might be in the particular instance. Regardless, it INSTANTLY tells you if there's an error (most common use of it) or deliberate alteration. Doesn't have to be "add"... you can byte-wise XOR, binary shift (=shift if the bit is 1, not if it's 0, compare the result byte after going through the entire program this way), and so on. Maybe even do more than one such algorithm because even if a REAL SMART programmer came along and knew what you were going to do, it's basically impossible to make it pass if multiple methods are used.

Kind of a no-brainer in the embedded processor world for finding tampering.

Darkhorse15T

I also have a pair of JBA short tube headers CA legal for sale if you'd like them. new never installed. I wanted to be smog compliant but hey, you only live once.[/QUOTE]

I’m interested in your headers if still available. Send me a PM I’m in the LA area as well, thanks!

Jeep_junkie

I just remembered that my car DOES have the skip shift feature tuned out, so technically the factory PCM image has been altered. It still passed without any trouble.

joecar

It seems that prior to 2006 they do not have the checksum/VIN/OS value in their database, so they don't know what they should be.

Question is: what values do they actually have (if they have them at all), what happens if they see the values change...?

RevGTO

iTrader: (12)

It would be interesting to hear from more guys with modded tunes who have been tested. I thought they just tested for emissions-related codes and emissions components that showed "not ready" (or is it "ready" per earlier posts?).

So for instance, my M6 Formula which only has skip shift tuned out and altered timing tables might pass. But leaving aside visuals, would my 2000 A4 with 2002 OS and massively modified tables with emissions DTCs set to "not report" pass?

patSS/00

iTrader: (6)

Also there can be factory software updates that may or may not be installed, since that's up to the owner. I know there was one for 2000. So different checksums possible for the same car.

Jeep_junkie

I was told by a few people I ran into during my clean smog quest, and it's a very simplistic description, that smog techs reset the readiness monitors at the end of the test and check them for readiness one last time. Obviously, any monitor that's been set to not report is going to show up ready by default, and at that point the tech would know that it's been manipulated, resulting in a fail. Now, this is what I know from word of mouth. I have not experienced it myself. It really would be nice if somebody could confirm if this ACTUALLY happens.

wannafbody

iTrader: (2)

According to the emissions sticker on my 2000 TA, it doesn't list the EGR as an emmisions device. So removing that and tuning it out whouldn't fail a visual inspection. Maybe it changes a computer setting on 98-2000 and is able to be detected. I'm not sure.

SarGntoperez

I’m interested in your headers if still available. Send me a PM I’m in the LA area as well, thanks![/QUOTE]