I received that code. I changed all spark plugs and coils. Still got the code for cylinder 2. I want to know if I should check the injectors , or is it wiring most likely. I checked the wires and they don't seem worn out.

 

what year/engine is your car? Do you notice any performance issues or other symptoms or is it that you are getting the CEL and it won't go away.

A P0302 is saying a misfire was detected on cylinder #2, which can be caused by ignition, fuel delivery or compression issues. Injector issues are not all that common but you can always try swapping #2 and #3 to see if the fault changes. As to wires, I assume you are referring to the harness that powers the coil? you can look for cracks in the connnector and clean the contacts to #2. After that you may want to measure fuel pressure at the rail and consider doing a compression test. Any signs of coolant loss with no visible leaks (suggesting a head gasket issue)?