Prius 2014 Plugin Error Code P0300, P0125, P1449

I got these error code from my Innova 3160 P0300, P0125, P1449. Took the car to the dealer for 25K service and they ran more test on TechStream. They say because I have aftermarket Viper Alarm, aftermarket speakers, aftermarket inverter cover which could be causing the error code. But nothing show up on the dash. Should I be concern? I ran the tester on my friend Prius Plugin 2014 and she got P0300. I did not check the other error code. P0125 is coolant, P1449 look like a bad Solenoid or battery coming soon. By the way, the dealer say the inverter cover will void warranty. So if your thinking of taking car in for service. Remove it. He say it could cause over heating. I told him the Lexus CT200H has it. But this is a Prius he hold me. Dealer are picky