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Looking at purchasing a 991.2, and had a shop do an OBD scan (the car is not near a Porsche dealer). They produced the attached fault codes report. Looks somewhat concerning to the untrained eye. Anyone have insight into whether this could simply be the result of a bad 12v battery - or something more problematic?
Given that multiple unrelated problem domains are presented there, I am inclined to think the battery is underlying at least some if not all off those. These cars are crazy sensitive to voltage issues that present in old/aged batteries.
I would ask them to replace the battery now and then clear all codes and then drive for at least long enough for all the emission (I/M) sensors to go ready again. At that point I would pull codes and see what is what.
Last edited by user 93281574; Jul 18, 2025 at 07:13 PM.
My first guess is the battery. If that checks out ok then my next guess is water damage. There are just way too many different & unrelated fault codes. If the batter is not the issue, I'd probably stay away. But that's just me.
Thanks, all. To close the loop, the selling dealer indicated that it could clear the faults but there would be no guarantee that the faults would not reappear (i.e., no attempt whatsoever to diagnose root cause). Not a fly by night dealer, either. Needless to say, I passed.
Good call on running away on that one. Post the Vin/Serial number in your reply. Future buyers of said used 991 just might google that Vin number to see what pops up. Google will find it in Rennlist and direct to this thread. I would advised any used car buyer to google the Vin on any used car purchase.
Last edited by SilverSFR; Jul 24, 2025 at 08:01 PM.
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Fault codes
