So I bought this car last year, a 2003 toyota echo, and have found that the A/C blows cool, but not cold air. it works best on the freeway, but in the city, not so much. I assumed it just needed some refrigerant. When I went to add some, A/C running, compressor engaged, I found it the low side running at 55 psi. That seems a bit high, right? Supposedly, an active system should be running 25 to 40 psi on the low side, with 30 being ideal. I dropped it down to 35 psi until I figure out what to do and now the A/C doesn't so squat. Do you think whoever overcharged it already caused damage to the system? What can/should I do now?