Toyota Repair: Check Engine light, emission control system, model check

Question
Two months ago this came on, along with the battery light. i got a new alternator, battery is ok. Also just got new brake lines a few weeks ago. Now the check engine light is on again! i have a regular mechanic and i'll take it there, but is there anything I can check in the meantime? Can fluid levels affect this? Thank you. Laurel

Answer
Fluid levels have nothing to do with this, depending on the year model check engine lights are turned on mostly by emission control system malfuctions and in later models also by engine performance problems. Let me know hat the diagnostic trouble code numbers are and the year/model it is if you need to post a follow up.