Thanks all for the input...I only lean toward the "its the winter blend" theory because I ONLY need to replace a sensor in the WINTER. Never have I had to replace one in the warmer months. All 4 of mine were replaced last winter...I went the entire spring,summer,fall, with no problems. Winter hits this year and BLAM...I needed a new Cat and after that was replaced another O2 sensor went. Coincidence????
I will try the lower octane stuff in my next tank knowing that it will not hurt the engine...only performance. But thats OK...it is winter and I'm not exactly flying around these Chicago roads!
