One problem related to o2 sensor has been reported for the 2003 Ford Explorer. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Ford Explorer based on all problems reported for the 2003 Explorer.
I bought my Ford Explorer XLT back in June of 2015. Since then I replaced my oxygen sensor do to a fault in the system and melting back in Aug. 20015. The SUV wouldn't start because of it and had to be towed. Since I purchased and had replaced the oxygen sensor by a Ford dealer, I noticed the SUV having power failure even from a complete stop and now the over drive off light flashes; this started in the beginning of Nov. 2015 I noticed that there is over 2755 complaints of transmission problems and failures exactly the same as mine, but not one recall. This is a issue with the SUV themselves and not owner error. I have children and don't want to end up stranded in the street or side of the highway due to transmission failure. There has to be something causing the transmission to break down or fail and I refuse to be the the blame nor pay thousands to Ford dealership to fix a flaw in there own SUV. A recall needs to be made for this problem and it is clearly a manufacture flaw.