Yes, you need to make it stop.
Pinging causes cylinder and valves to overheat, you can end up with "tuliped" intake valves or burnt exhaust valves, if it continues.
Pinging can be caused by a few things.
Carbon(unburnt fuel) build up in the cylinder gets hot and ignites the fuel mixture on compression stroke slightly before the spark plug fires, the "ping" you hear is when the two separate explosion wave fronts meet.
Retarding the timing so spark plug ignites the fuel before the carbon can corrects this but you lose power.
Cleaning out the carbon is better, but the carbon is there because something else is wrong, usually mixture was too rich at some point, or engine is running to cool.
An engine should run with coolant at about 200deg, smaller 4cyl sometimes run cooler and that can cause carbon build up, make sure you have a 192-195deg thermostat installed, that should keep engine temp up in the 200deg range.
There are a few ways to clean carbon from the cylinders other than removing the head, you place cleaners in the intake, read all the instruction so you don't damage anything.
And MAKE SURE you unhook the negative battery terminal for at least 5 minutes to reset the engine computer, this is needed after any engine work or computer will continue to use old settings, forgetting to do this can cause pinging as well, and even if you find the issue and fix it you won't know it unless you do this.
Running too lean causes pinging, bad O2 sensor can cause this, low fuel pressure as well.
Lean mixture doesn't cool the cylinder as much, when surfaces get hot enough fuel is pre-ignited just like carbon buildup would do.
The computer bases the air/fuel mix on what the O2 sensor tells it and what the assumed fuel pressure is, computer doesn't monitor fuel pressure, so if pressure is low then injectors are not opening long enough, so lean mixture.
If it pings as bad cold as warm then it's probably not an O2 sensor since they are not used until engine gets warm.
A vacuum leak leans the mixture as well.
EGR system issue can cause pinging, exhaust gas helps cool the cylinders, yes it doesn't make sense but it is true, lol.
remove EGR valve, if you have one, and clean it, make sure it is all working as it should.
Higher octane fuel can lessen pinging but the 2.5l can run just fine on regular, so I would find the problem.
Higher octane doesn't ignite as easily under compression as lower octane gas which is why pinging is less, lower octane is easier to ignite.
I don't think the 2.5l has a Knock Sensor, if it does then it may be unplugged or bad, the knock sensor tells the computer to retard the timing if "pings" are detected.