Check engine light AHHH!!!

You are right! It has not been serviced properly. However I had a engine flush, oil change, and the sensor changed out. But its still reading the same code. 4 shops have told me it could be oil block up. I really like this car. Its a perfect size for me. I can take it to the lot today to get it fixed or I can get another one on the lot. (however with used cars you don't know whats wrong with the car) I really don't know what to do. I am new to Dallas, with just me and my two girls. I don't know the best thing to do. Any suggestions? (oh and the engine is great)