I'm no A/C tech, just a DIYer with Fieldpiece diagnostic tools and a desire to learn. I have an Amana 12 SEER R-22, Non-TXV residential split A/C about 10 years old. My home is 2200 Sq Ft. located in Houston, TX.

I was wondering if the high side reading is too high?
If yes, would the evaporator need cleaning, since it's never been cleaned?
You opinion of the system will be much appreciated?

My readings after 20 minutes of run time are:
Low side gauge PSIG: 80
Low side line temp: 65.5 F
Low side gauge temp: 48 F

High side gauge PSIG: 330
High side line temp at condenser: 98.4 F
High side line temp at evaporator: 101.5 F
High side gauge temp: 138 F

Outdoor ambient DB temp at condenser: 100.1
Indoor WB temp at return grill: 68 F

Nearest grill to evaporator: exit DB temp: 77F
Nearest grill to evaporator: exit WB temp: 56F
I think TEET should be: 54.5
I think non-TXV target superheat should be:12 ((68x3)-80-100) /2
Actual superheat is: 17
Filter is clean.

Your evaluation will SURELY be appreciated. Thank you in advance, Jim.