They must be missing something. Already replaced the PCM? Did they actually probe the sensor to make sure it's working properly? Perhaps the sensor may need to be shimmed, maybe the old one was shimmed and the tech didn't think anything of a shim. Some motors from the factory may have been shimmed due to low clearances, there is an air gap spec most likely, it's just not officially serviceable i don't think. I have shimmed crank sensors before for issues like this. Crank sensors will cause all kinds of issues, usually just no start, but sometimes this.