Help, LCD Display

how do I make it say it once?

Move the irrecv.resume() out of the switch/case.

case 0xFF6897:
        lcd.write("Howdy");
        digitalWrite(52, HIGH);
        break;
    }
     irrecv.resume();
  }

Remove the delay from the switch/case for a more responsive sketch.

Guess they didn't have ir remote plans in mind:

pins 0 & 1 are for the Serial port, they have noting to do with IR remote.

I put it on those pins because I looked up a diagram and that was how it was wired.

What you saw was probably the wiring for a LCD to an I2C expander. Not applicable for your LCD.