BD-Power had me buy a new thermocouple for my X-Monitor after my pyrometer had quit several months prior, often reading nothing but ----. The new probe worked for about 3 weeks. They said I'd have to send the whole system back in, out of warranty, and pay for them to figure out and fix the problem. I have intermittent readings, peaks at well over 1,800 degrees at WOT so I'm not sure how reliable these readings are. I've been to switch to mechanical gauges but it doesn't sound like they are a whole lot more reliable.