Question a/b irretrievable OBDII "V.A.L." info

Question: What is the V.A.L. report/log that the OBDII system produces? Anyone have any real expertise on this? Specifically is there any explanation as to why a P-dealer would be unable to retrieve the V.A.L. data from my car? Backstory: �03 996 6sp coupe, 30k miles, CPO warranty still in effect, stock driveline. Car got a routine 6/60 service, RMS replacement and fresh clutch at dealer about 4 months ago (old clutch was fine & had 40% left, but since the RMS replacement was under warranty the clutch only cost me parts). Anyway, out of the blue I got a steady CEL about a month ago. No other detectable sign of trouble. Took car to same dealer, they indicated the catalytic converter on bank #1 had gone bad, so they replaced it under warranty. Last week a steady CEL popped up again. So, dropped car at dealer again. This time it was the cat on bank #2 (Code: PO430, which is just a generic code saying �Catalyst System Efficiency Below Threshold (Bank 2)�. Dealer has replaced the 2nd cat under warranty. So far so good. BUT, the dealer indicated that they were unable to retrieve the more detailed �V.A.L.� report on the emmissions system out of the OBDII system. They said they were only able to get the basic OBDII log data, but not the V.A.L. details. They vaguely speculated that maybe my car�s previous owner perhaps installed some kind of aftermarket engine management software which might have caused the VAL report to be masked or something?? I asked the service rep on the phone what the VAL stood for, and he did not know. He just said it is �the more detailed information.� I�m pretty handy with suspension, brakes, oil changes, but NOT with this OBDII/software stuff. I�m in uncharted water here. Anyone care to educate me? Thanks!

No expertise, but would kindly offer my .02 Sounds like they are grasping at straws. If they suspect software has been installed, ask them to flash it to stock and be done with it.

Quotes source post: 6545161

VIN, Calibration ID #1, Calibration Verification Number #1, Calibration ID #2, Calibration Verification Number #2, and In use Performance Tracking available. And in multiple ECU equipped vehicles each ECU can have its own Cal ID and Cal Verification Numbers. Not sure how the CALIID, CVN numbers arrived at. Generally in firmware the image has embedded in it version subversion and other info, Crc numbers, whatever the engineers feel is necessary to clearly ID the firmware image and whatever Crc is necessary to ensure the image is intact and complete. Or in some cases the firmware image contains code that when invoked generates the necessary info. For instance the Crc may be generated on the fly and not stored someplace. The act of generating a valid Crc and the generation of a valid Crc is used to confirm the integrity of the image, that it has not been tampered with. If a static Crc used for instance, 3rd party firmware would just return a hardcoded Crc value when queried for one even though the image over which the Crc was generated is no longer the same as it was from the factory. If I understand your post correctly it reads like the dealer or a tech tried to fetch these CAL ID and CVN numbers and was unsuccessful. This strongly suggests to the dealer that car's ECU image has been tampered with and by tampered with read an aftermarket ECU image has been used to replace the factory ECU image. And apparently not a very sophisticated aftermarket ECU image at that. One course of action would be to have the ECU reflashed with the factory image. This will probably cost you. However, the reflash may not work cause the reflash operation may require it obtain valid CAL ID and CVN numbers from the image before the reflash can proceed. The assumption is that if there are not available this indicates a failure of some kind of the ECU and then replacement of the ECU is the next step. Sincerely, Macster.

Your car has likely been "chipped". Your dealer can easily check the "Tamper" condition.

Loren and Macster, Thank you for the education... even if I only partly understand what you guys are saying. Update: I talked to the P-dealer that CPO'd the car and sold it to me (only 6 mos & 3k miles ago). They seemed surprised that they would have been able to get a new CPO warranty on the car without retrieving a valid set of data from the ECU. They offered to take a look if I bring them the car (they are 1 hour away, not my closest dealer). I think its reasonable to expect an ECU to be stock & uncorrupted when buying a CPO car from a dealer. (don't laugh!) Hopefully they will agree and do whatever is necessary to re-set the ECU back to stock. Since there is currently nothing wrong with the car, this seems like the right time to get this resolved, rather than waiting until some potentially major mechanical event happens and PCNA tries to deny CPO coverage because of the bad ECU. Do you guys agree that's my best course of action?

Unless there was a physical chip change (which is unusual today) they should be able to re-program the DME to stock. Then test it for validity. If you are in Northern California and need someone to do this I can help (I have a PST and PIWIS).

Loren, thanks. You have a PM.

Quotes source post: 6552136

or tried to reflash it, etc. then I'd take car back to dealer and have this sorted out. Could be dealer skipped the part of the CPO inspection that requires pulling this info though I'd think Porsche would require a printout as part of CPO paperwork. Could be Ecu starting to act up and could go in full fritz at anytime. I'd be leery of attempting any home grown fixes though if you want to have someone with proper equipment and know how double check for you before you make run to dealer, as long as no reflash (if even possible) attempted I see no harm. The idea is that this double check should leave no trace that it was done so as to not put at risk any CPO warranty that can apply. These Ecus ain't cheap and you don't want to have to buy one if you can have it replaced under warranty. Sincerely, Macster.