where could the splashed coolant be coming from?

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i turned on my car just fine, as i drove in reverse out of my drive way, car made a strange sound as i alined my stearing wheel. i thought it was my power stearing but when i open the hood there was splashed coolant tords the front right of the radiator. i cant see where the splash could have came from. what could it be? what do i check? this is the first time this happens. my check engine light is on but its due to the cat. after this incident, the idle reads at 3/4 as I drive 20/30 mph.