RE: Mt 57..... Runs like crap
A "whacky" sensor will also drive you nuts. Sometimes they fail completely and then the engine won't run, but sometimes they just misfire making you think it is the plug or possibly the ignition box itself. Terry at CH Ignitions says they fail in the "whacky" mode about 5 percent of the time. I have also had them go bad if they had gasoline dripped on them for a bit; like from a leaky seal.
AV8TOR