so on my 2004 rx8 , the other day i changed my oil and oil filter and than the next day the engine light came on it hasnt been on before and i think its wierd it came on the next day. any comments or possible ideas what it could be?

 

Go to an auto parts store like autozone and they can figure out the code for you. This will tell you what you're dealing with. After that search here for possible solutions to the code.