The 4B11 motor that comes in the 2008+ EVO X and 2009+ Lancer RalliArt does not have a timing belt. It has a timing chain that turns the cams. The computer keeps track of how much the chain stretches over time. It will tell you when it is time when all the systems are working properly. If you get the triangle warning light and the car has a rough idle, it might have jumped a tooth or two. A couple more teeth jumping means that valves and pistons start crashing together. If your chain has been confirmed to be stretched and you have a rough idle, don’t drive the car at all.

A recent customer never did a full service and rarely changed his oil in 80k miles. The timing chain stretched enough to jump quite a bit. It bent the intake valves, when the piston came up it smashed the valve stems into the guides to where they broke off. One of the valves got bent into a perfect little taco. It was able to get knocked back into the intake manifold for an out of the park home run. Here is a new redesigned timing chain (with less links to rub against each other) that still will stretch prematurely if you don’t change the oil enough: