Don't know much about the Autometer gauge but if it hooks to your stock sensor, like Dave says, you probably won't get much info out of it. That's a narrow band sensor and will only show values right around stoich. The wide band with it's own sensor is the best way to go. I'm running a PLX M-300 also. My only complaint with it is it's hard to read in the sunlight. One of these days I'll pop out the plastic wiindow and put a lear one in or one that's just lightly tinted.