I have a 1999 Subaru Legacy Outback 2.5 that is overheating

Yes probably is related. I suspect a blown head gasket.

Do you have a lot of white smoke out the exhaust?

Check the coolant level and make sure the cooling fans come on when it is hot. Check the coolant for oil and the engine oil for coolant as you have a Subaru and head gaskets are always suspect. Mis- firing could make it run hotter so you should probably replace the plugs and the wires.

Hi, i have read a lot about the head gasket and i am quite sure it is that the issue, but i am concern about the something else gone bad, it is showing a lot of smoke every time I idle it, the fans are working fine, but the thing i notice today, is that whenever i idle the car even parked, the hose gets more pressure and the radiator cap is cold even when the temperature on the dashboard says its hot.

Maybe you need to replace the thermostat.

" it is showing a lot of smoke every time I idle it " Well there you go, sounds like a head gasket to me.

The hose gets more pressure because the cooling system is being pressurized not only by the heat of the engine, but also by combustion gasses from the pressure of the combustion process. Head gasket failure is very common on Subarus especially the higher mileage units. Getting rid of it or repairing it are your options.

Check your overflow bottle and if it is filling up to the top while driving it will start popping the lid off and your coolant will go all over. This is a pressure build up and either a cracked head, cracked motor block, and or head gasket. You have to be fluxed and pressure tested to confirm. If it is like mine was even doing all that expense of replacing you waste your time and money because it will still give you problems as the motor heats up and cracks will separate allowing coolant into cylinder walls, into oil, and or out your exhaust pipe like a whole lot of white steam. Most times replacing engine is the answer but you can still buy another faulty cracked engine if it is a used one.