The temp seams high if it's up at the other end of the normal scale?

Has it had a head gasket replaced recently?

That's still a narrow band air - fuel ratio meter. It is only accurate at 14.7:1 air fuel ratio, that's a limitation of the sensor not the meter. You can "sort of" guess the air fuel ratio away from 14.7:1 with these but very inaccurate. Really they only give a Rich - Stoch - Lean condition. Even if you could 'calibrate' it the sensor will still drift. I bet the ppl who designed your $80 one just didn't want to s**t you that calibrating would make it accurate.

Wide band A/F ratio meters are a different story with their own dedicated controller and sensor. Upwards from $400. They are accurate.

Yeah autometer A/R guages are only to give a rough idea, but all he is saying is you get a rough idea... but you'd be suprised what can be done with one