I need to put something to rest once and for all. I have a 2000 4Runner, 3.4 LV6, auto, 4x4. My check engine light is on for the fourth time in the past six months. Does anyone know all the inputs that can trigger the "check engine" light to come on? Are there like a thousand or just a handful? I ask because so far I have replaced the Mass Air Flow Sensor and the O2 sensor before the catalytic converter, and I'm wondering if the other O2 sensor is now shot and if this is the last main thing that inputs into this light. Thanks for any help.
Gus