Po452 and po446 on 04 chevy silverado have replaced fuel pressure sensor and reset but code po452 keep poping up

P0452 evap control pressure low, P0 446 evap vent contol circuit. Becuase you have P0452 you are dealing with a eletrical issue whether you have positive tank pressure or negative pressure, The tool for this is a volt meter.452 happens when you positive pressure and the FTP reads less than 0.1 volts.You need to jump the signal and the reference and monitor the take parameter on a scan data you should read reference voltage.Now if you dont have a scan data tool. inspect the wire for any breaks or shorting 2 thing of concern broken wire to the FTP or a ECM is needed.