I have had my 958.1 S for over a year now periodically get scary seeming fault codes reset them with my scan tool and then they never come back or don't come back for months, am I correct in assuming if the same codes aren't coming back it is some kind of electrical gremlin like a bad ground, bad wiring or weak battery? I have got minor evap codes a few times, suspension vent valve stuck on code, PCM failure code, knock sensor 4 code, signal stuck open or rear seat heater failed etc. The car drives fine.

How old is the battery? Also have the coils ever been replaced - they can crack and that sometimes throws codes. ​​​​​​

I have had a few different issues with mine over the years, failed coils, wheel speed sensors, air suspension, battery. Some of those codes I have never seen (evap, vent valve and knock sensor). Some random codes can relate to failing battery or a wheel speed sensor but wheel speed sensor is usually a defined list of codes, not the ones you are showing. First thing I would do is keep the battery charged to try and outrule this. See of any of these occur when the battery is fully charged. If they don't re-occur, you may need a new battery, if they do then you may be looking for a gremlin.

With the evap code, pay attention to hard starting, especially after refueling. If you have those symptoms as well as the code you should look to replace the evap purge solenoid ASAP.

never had hard starting even in minus 30c, battery could be 18 months old from a Jaguar/ Landrover dealer where I purchased supposedly but I trust anyone associated with that brand as far as I can throw them. Coil could be old its around 150,000kms so I would hope they have been done 1 time at least and would the cracked coil throw a misfire on that cylinder not a bunch of random codes. To clarify these codes are all seperate events over the last year, leaning towards battery or gremlin because of the randomness and being from all over the car.

The coils are fairly obvious when they start failing, the car will run rough and you will get noticeable misfires.

One thing I have learnt with these cars is if you get a code and it seems to run fine, clear the code and don't worry until it comes back again. Although I haven't had a couple of yours I have had some other random ones. Bear in mind some owners have had electrical gremlins due to water ingress corroding wires in the front foot wells due to blocked A/C and cowl drains. If they re-occur might be worth looking into this.

Cleared the code(s) and still none have come back, maybe Porsche thought that as they age random codes would get people back to the dealer because these things are actually TOO reliable LOL! Launch x431 pro was money well spent especially considering my nearest dealer is over 700km away.