if you still have your cats ,they may be a little clogged up making the ecu read a misfire, I have no cats and have run 110 without any problem,, yet my tune was NOT setup for it so my car went slower,, took almost 400 miles for it to clear itself,,,no plug or o2 change. just driving,,some slow,and some burst to a little over 100. but this in the V8 not the 6,,,,,,,,,,,, jim

I now only use 93.