I'm trying to rig up a zener diode for use as a voltage clamp but I need some help. I'm running a 2-bar MAP sensor with an ecu that cuts fuel at 12-13psi. Assuming a max voltage of 5v, I think I'd need a zener diode that clamps votage at 12psi, or 4.08v, correct?

Anyone know which diode will give this effect?

Thanks!