Toyota Repair: 2000 Rav4 engine light, emission control system, input sensors

Question
Hi  I just bought a 2000 Rav4 last month (not nder warenty) and the engine light just came on this after noon.I've had the oil changed, and the previous owners had replaced the timing belt, so I'm at a loss as to what the trouble could be. It runs fine,and I can't see any reason that there would be an issue that would cause the light to come on.A frind of mine siad that it might be either the O2 or the fuel sensor. If so, how much should it cost to fix it? Thanks

Answer
I have no idea because I don't know what's wrong, the check engine light is triggered most of the time because there is aproblem with the emission control system or one of the input sensors for the computer, in order for me to have any kind of answer I would need to know the diagnostic trouble code that is stored in the onboard computer, this code can be retreived by connecting an diagnostic scantool to the car to find out what the codes are, most autoparts chain stores will do this at no charge, try to locate an autozone/ kragen/or even aamco transmissions, they all advertise that they will get the codes at no charge to the customer, once you have that information you can get back to me and I can help.