I'm planning to build my own A/F meter, and was debating a "lean" alarm that would go off if things leaned out under load. However, as I understand it, the A/F ratio goes very lean on deceleration.

What is "typical" AF meter behavior under various driving conditions? I was thinking of creating something that tied into the throttle position sensor output (S4), and would only sound the alarm if the throttle were open fairly wide and things leaned out.

Also, what does an O2 sensor read while cold? I don't want the alarm going off while it was cold, though a throttle sensor would take care of this.

(I'm a Computer Engineer. I am capable of designing the circuitry needed to do this.)

-=Russ=-