The PCV valve on the 99 galant is the piece of plastic shaped like and L on the top of the engine manifold. It has a piece of tubing going from the valve to the intake. You can easily just pull it out from manifold,take tubing off and replace with same PCV valve. then put everything back theway you found it.
The EGR Valve on the 1996 Mitsubishi Galant is located underneath the Exhaust Manifold.
The strainer valve on the Mitsubishi Galant 2004, 2005, 2006 models is located next to the engine manifold.
The EGR valve, on your 2005 Mitsubishi, is located beneath the air cleaner. Remove the air cleaner housing. The valve should be visible and labeled.
on my 96 2.4 its right on the valve cover,has a hose going to the intake manifold
The EGR Valve is located at the back part of the Engine. When you open the hood, you may bow down next to the wall at the back of the engine and you can see 2 hoses that goes into it. To know what it looks like, type it in Google, 2001 Mitsubishi Galant EGR Valve then take a look at it on the location that I have said.
one per valve
Expansion valve is located on the A/C Evaporator Core. Most of the times you have to remove the whole dash to reach it/ replace it. Good luck.
Attached to the intake manifold
10 in 10 ex
PCV valve is a gauge for gases to pass through to engine. It is located close to oil fuel tank center engine, the gasket cap must be removed to access it.
on the upper left side of youre firewall
http://www.scribd.com/doc/6382741/Mitsubishi-Galant-2003-Systeme-de-Chauffage-Et-Climatisation- check section 50-40 AlexR