Having a few A/C issues, when we first got the car 12+ years ago, I noted the econ light was stuck on, the seller had the A/C fixed at the time (not sure what was wrong), and it was ok for about 10 years, my servicing company, did suggest there had been a refridgerant leak at some point, as they could apparently see traces with a UV light in the engine bay, however they could not say if that was from when the car originally had an issue and I've no idea how long it would remain with traces of a leak?

about 2 years ago, something funny happened, we were on a long drive home one day, and there was a notisable woosh from the engine bay and the climate control display dropped to 5 degrees C on both passenger and drivers side? the actual air also blew through very cold, much colder than normally, and an hour later, when we were home, I noted condensate under the car which was unusual. In theory 5 degrees C is not possible on the climate control, it goes down to 16 degrees, and then below that it just says LO. I pushed the Temp Up arrow multiple times and it climbed back to 16 degrees and back to LO as normal, and then has continued to display settings normally since, but the cold air has never been good since. But no errors logged on VCDS. I wondered if that was a sudden loss of gas, maybe a leaking compressor or something.

more recently, last couple of weeks, noted the ECON button is stuck on again. I've scanned the car tonight, and it's showing a 00819 - High Pressure Sensor (G65) 07-00 Signal too low error.

from what I can see, it's most likely because it's lost the gas or it's a faulty sensor?

which one would you start with? the sensor, I think it is part number 8E0 959 126C (Vin WAUZZZ8E38A106124). Is this correct, and would you get a genuine one or aftermarket? If the sensor is worth a try, I might have a go myself,

Or would you recommend I find somewhere to pressure test the system and if good, re-gas as the first step?

Thanks
Paul