so you had a shop fix it and they gave it back with the cel still on? if thats the case, avoid that place from now on.... that's some real BS

take your car to auto zone or another parts store that does a free scan and find out what your cars problem is. they will give you the code , and most will tell you what you need to do to fix the code, if they dont then post the code here, someone will know where to point you to.