Hi
An interesting thought, but the caps and rotors are only a year old although I've had to clean one recently due to tracking - these cars eat caps! Maybe worth a look and clean again?
More reading about my X11/4 and X11 connector (I have both) seem to suggest that the signal available is simply the O2 sensor output which I think I've convinced myself wont actually tell me much.
How does one measure the compensation value the closed loop system is using to keep the 14.7:1 ratio?
In the electronics industry it's easy, we simply measure the input.