Engine performance reduced and sluggish to drive after engine clean

The Check Engine light is the main clue staring you in the face. The Engine Computer detected a problem, set a diagnostic fault code, and turned the light on to tell you. The place to start is by having that code read. Many auto parts stores will do that for you for free, but remember they're in the business of selling parts, and they often aren't mechanics. Fault codes never say to replace parts or that they're defective. They only indicate the circuit or system that needs further diagnosis or the unacceptable operating condition. Especially in this case, it's unlikely a sensor has failed. It's more likely water got forced into a connector or a connector got blown apart. The problem could clear up when something dries out, but you still want to know what the fault code says in case this happens in the future from driving in the rain.