Q&A

The 3 lights came on and I brought the car to the dealer who replaced one of the 4 O2 sensors. 9 days later, they came back on again. There were two factors that were present each time it occurred. My gas tank was about 1/8 full and I filled the tank. Next day, the car had been sitting in the sun and the outside temperature gauge read over 100 degrees (temp was actually about 80). Within 10 minutes of the temp reading and driving off, the idiot lights came on. I don't think it is the O2 sensor - please give me your thoughts?