Just bought my 15yo son a 2006 Wrangler with 111k miles. 6sp manual, I6. Seems to run great. We test drove it twice before buying, no issues. Drove home 30+ miles on highway and have driven it several times since, no issues. Last night my son drove around the neighborhood for about an hour to practice driving manual. Mostly stopping and starting, rarely getting past 3rd gear. He went on the highway once to shift through all 6 gears. The check engine light came on right as we got back home. The on-off key thing this morning showed P0133 which appears to be an O2 sensor issue. Any advice on where to start with addressing this? The obvious choice would be replacing the sensor, but we don't have the tools to do it ourselves, and my Jeep guru brother lives 4 hours away. I don't want to blindly trust a mechanic before knowing more about what might be going on. Could his shaky driving have triggered it? He didn't do anything awful, but he did stall several times and had some less than smooth shifting a few times. I drove it around this morning and it still seems to be running fine. Any advice is appreciated.