While testing this weekend I noticed a couple of what I thought were hiccups during a couple runs. The AFR would jump to 14.38 or so and then back close to target. I also noticed that near those times the RO2_Corr value went to zero. For fun, I loaded swapped in the first tune of the night to see if any of my changes were the cause. On that run the car ran the same time as at the beginning of the night, but the AFR was a constant 14.38 and I now have no fuel correction. My guess is the AFR issue is a bad O2 sensor, but would that also affect the correction reading? I've read about verifying a "R_RiOhms" value but I cant find it. Is that because I have the base system? If not, where do I find it? Can I test the sensor without the car running, since I'm concerned about the 14.38 AFR? Finally, if it's bad, what sensor do I need? Thanks for any and all direction!