Hi Alan,

>>> To get back to my question and rephrase it slightly, does it make sense that the ecu would lean the engine under knock?

To put this in perspective, I am not the first to work on this. Previous attempts have included, as far as I know, 2 new knock sensors, an ECU, a cam sensor, a check of the wiring, a set of plugs, a coil pack and God only knows what else. When someone else suggested engine mounts the customer bailed out <<<

That certainly puts it in perspective, without teaching someones granny to suck something we both know that the main function is to retard the timing and then creep it back to the optimum CA.

It may well make sense for the ECU to reduce the fueling at the same time, however it would make just as much sense for it to do the reverse and increase fueling.

I have a similar vehicle at work and I will monitor the Injector time whilst activating the Knock sensor in the morning and see what the results tell me.

Regards Mark