Where is the fuel sensor located on a 2003 Toyota Celica GT?

The Oxygen sensor is located in the exhaust one before and one after the catalytic converter. You may have a vacuum leak or other problem and not necessarily a bad O2 sensor. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online