I have been told by few different people to run Unleaded race gas like MS109 or Sunoco 104. Because all the leaded race gas leaves film over O2's. And the widband does not register accurate.
C16 isnt that hard on the WBO2s, its that leaded and loaded with MMT 110 crap (turbo blue or whatever) you buy at gas stations that kills O2s.
I could get a whole season out of Bosch LSU sensors running straight C16, as long as you arent daily driving with C16 the sensors will last a while.
Congrats on the times, nitrous is the way to go in the summer :beer: