Help combining code

Im having a hard time combining these two codes together any help is appreciated, thanks.

int Vout = 0;
int egtPin = 2;
int egt = 0;
// include the library code:
#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(7, 8, 9, 10, 11, 12); 



void setup()
{
    lcd.begin(16, 2);
    lcd.setCursor(0,0);
    lcd.print("O:");
    lcd.setCursor(5,0);
    lcd.print((char)223);
    lcd.setCursor(6,0);
    lcd.print("F");
    lcd.setCursor(9,0);
    lcd.print("W:   ");
    lcd.print((char)223);
    lcd.setCursor(15,0);
    lcd.print("F");
    lcd.setCursor(7,1);
    lcd.print("EGT:");
    lcd.setCursor(0,1);
    lcd.print("PSI:");
}
void loop()
{
  
Vout = (analogRead(egtPin) * .004882814);  
egt = (((Vout - 1.25) / 0.005)* 1.8) +32;//egt in F
  
float resistance, voltage, r_fixed, T0, T, R0, B, F, Toil, F1;
T0 = 348.15;//initial temperature for calibration
R0 = 150;//initial resistance for calibration
r_fixed = 138;//known resistance
B = 3947;//B for normalization



while(1)
{
voltage = analogRead(0)*5.0/1024;// Renormalizing from 0 to 5 volts.
resistance = voltage*r_fixed/(5.00-voltage);//find unknown resistance
T = 1/(log(resistance/r_fixed)/B+1/T0)-273.14;//find temperature from unknown ressistance
F = (T * 9 / 5 + 32);

voltage = analogRead(1)*5.0/1024;// Renormalizing from 0 to 5 volts.
resistance = voltage*r_fixed/(5.00-voltage);//find unknown resistance
Toil = 1/(log(resistance/r_fixed)/B+1/T0)-273.14;//find temperature from unknown ressistance
F1 = (Toil * 9 / 5 + 32);



  lcd.setCursor(11,0);
  lcd.print(F,0);
  lcd.setCursor(2,0);
  lcd.print(F1,0 );
  lcd.setCursor(11,1);
  lcd.print(egt);

delay(1000);

}
}

and

int OilPressure = 0;
#define aref_voltage 1.1

void setup() 
{
 
 analogReference(INTERNAL);
 
}

void loop() 
{
 
 
 float OilPressure = GetOilPressure(analogRead(3));

 delay(1000);
}

float GetOilPressure(int RawADC)
{
 float volt = RawADC * (aref_voltage/1023.0);
 float bar = ((2.1271 * volt) + 5.1075 ) * volt - 0.2561; // optimized
 float psi = bar * 14.7; 
 return psi;
}

I notice that you're changing the reference voltage for analog readings to suit your oil pressure, BUT your temperature ALSO uses analogRead. This will either need to have calculations changed (to take into account the new referrence voltage) or the relevant steps taken to switch back when reading temperatures.

Personally I don't understand why you don't put the analog read within your GetOilPressure function. It would keep all the functionality of this procedure together in one place.

This demo may be useful.

...R