About a month ago I was heading to my friend's house with the family on a 55. Came up on a slower driver, dropped to fourth and got up to roughly 70 while passing them. During acceleration, my A/C decided to start blowing hot air. For the rest of the trip it stayed that way.
Fast forward to now: I'm trying to get it fixed. Once in a blue moon it will blow relatively cool for about 5 to 10 minutes before starting to blow hot again. I took it to a local cheap shop today to have them attempt a diagnosis (closest Subaru dealership is an hour away). First thing they noticed was that my system was way overcharged. After further diagnosis they have determined it is one of two issues.
The expansion valve needs to be replaced. "No freon flow to high side from low side". The ambient temp sensor needs to be replaced as "outside temp stayed at 82 the entire time, even after a test drive."
From doing a bit of reading on the forum, it would appear that the outside temp sensor is not linked to the HVAC system and for some reason only gets its readings while driving a decent distance. I can confirm that it managed to hit about 91 degrees on the way home from the shop, albeit creeping up a degree every so often. It did fluctuate between 90 and 91. According to Google and my weather app it was around 93 at the time, so that's damn close in my mind.
What would your opinion be on it? I'd rather have some input from other owners before dropping $530 (total, roughly 338 if just doing ambient sensor & recharge or 440 if just doing valve and recharge) on something that may fix the issue.
Edit: From what I can find, part numbers seem to be 73730AG00A and 73531AG010 for the sensor and valve, respectively. Does that look right? I ask because the price they quoted me was $60 for the sensor and $75 for the valve. I find it odd that the sensor would be $50 cheaper online but the valve would be $40 higher. Granted I am looking at OEM as opposed to wherever they source their parts.