08 IS250 High Side on A/C too high
 

I have a 08 IS250 with a/c problems. I have changed the expansion valve, compressor, relay and condenser and still cant get my a/c to work. The low side is reading at 30-35 and the high side is anywhere from 225-275. The fans kick on, the clutch kicks on but the ac wont stay running. The coldest the air comes out of vents is 65 degrees and that is only for a short time. I drive on interstate and it seems to blow cold air out but not super cold air like it should. Any advice would help. Thank you.