The TCU for 92-96 Diamante's is located under the dash,behind the console.You have to pull the carpeting outward on both the drivers and passengers side,up front on the center hump(where your inside foot is when you're sitting).The drivers side is tricky because of the gas pedal.Behind the carpet is a small metal cover on each side which needs to be removed with a screwdriver.The TCU is fitted into a bracket which is bolted down up front right near the firewall.Remove the nuts(it is real uncomfortable getting these nuts off),disconnect the cables and pull it out any way you can.Installation is the reverse.
if its sohc it doesnt have , if its dohc its behind the lower damper i think
front valve cover at the left back corner. It screws in to the valve cover. There is a rubber hose conected to it.
If your Diamante is the Dohc 6 cyl. motor in it then you have to remove the entire intake manifold to replace the back 3 plugs I did it in about 4 hours with not many tools and I am a female. So it can be done.
The Mitsubishi Eclipse RS has a 2.0 DOHC 420A.
its under the passenger side rear tire
The 2012 Mitsubishi Outlander has double overhead cam (DOHC).
The 2009 Mitsubishi Lancer has double overhead cam (DOHC).
The 2008 Mitsubishi Outlander has double overhead cam (DOHC).
The 2011 Mitsubishi Outlander has double overhead cam (DOHC).
The 2013 Mitsubishi Outlander has double overhead cam (DOHC).
The 2012 Mitsubishi Lancer has double overhead cam (DOHC).
The 2008 Mitsubishi Lancer has double overhead cam (DOHC).