If you guys could get the same data from your cars and show me with a good running engine I could compare and possibly figure out which sensor is at fault and throwing the harmony out of the rest, from my data over only 6 seconds I would've thought the idle variation was considerably fluctuating.
I can see when idle variation was at 7, within the same second the revs, O2 sensors and other sensors were also fluctuating by higher margins, O2's were peaking at 500 just after a cycle of high/low/high idle variation, which to me might indicate a bad burn of fuel making the o2's detect more oxygen, since I've sorted out any ignition problems it comes back to timing, and if the CAS is playing up then it may be sparking late leaving less burn time, then o2's detect a bad burn and the computer goes through a correction based on O2 readings, yet the core issue might be the timing is slightly out and not significant enough to trip a code so the computer just keeps cycling the same corrections when any given cylinder happens to be the one that gets the timing kick.
Also when idling, sometimes a few plugs will be dirty, it varies which ones, others will be clean, and after i've gone on a longer drive cruising, they will all be spotless, so the bad timing shows itself more at idle when the air/fuel is in the cylinder longer, because at higher rpm it smooths out and the fuel tends to not burn fully anyway, hence the purpose of EGR & PCV valves.
