uhm try checking for codes.... you have to go to a shop where they have the circular diagnostic plug (which is under your hood) that thing reads like all the codes... but from what im thinking, one of your sensors might have went bad.
Another question, have you been working on your car by yourself or do you just drive it. What i mean by that is one time i took out my Mass Airflow Sensor and tryed putting an aftermarket air intake system in there; well it screwed up my car untill i got another MAF. my point is that you might have triggered something to make your sensor go bad. just which one is the question....