AC FOT system help FIXED

A friend asked me to take a look at their AC and I don’t know much about AC Systems other than the electrical side of things and very basic theory of operation. The AC works when driving but sometimes gets warm at slower speeds or at idle. I checked fans and the AC clutch is working also checked the condenser for blockage. So I hooked up gauges while ambient air is 90 the low side is 70 and the high side is about 340. Both the high and low are high which makes me think it’s overcharged initially however are there any other variables that can cause high reading on both high and low? I was told it hasn’t been touched but The gauges seem to tell me otherwise. If it is just an overcharge it’s gonna have to go to a shop with a recovery machine but I want to do my due diligence.

What is the pressure in both sides compared to abient with engine off and cooled down ? There are other things that can cause this issue such much oil as a cooling fan speed issue or the fins corroded on the condenser or too much PAG oil from.top up cans filling up the condenser

Agree with Andy, checking the system pressures after it's had time to rest can help ID a plugged orifice tube or TXV. The pressures should equalize pretty quickly on a working system.

Which vehicle is this, specifically?

It needed up being air in the system. Had it evacuated and replaced a line. Then had it recharged. Thanks for all the help.

Is there any recommendations on where or who I can learn more about using AC diagnostic gauges? I absolutely need to learn this through and through and have more than a basic understanding of the systems.