here's a pic of plugs L to R 3,4,6.
To the naked eye they all look the same, no one darker than another. If I took their labels off and mixed them around I would never tell the difference between say #1 and #6. They're Bosch WR7DC, in there since end of '09
Regarding running lean - when it was running on the MAF (the last 5 years <10k miles) I don't know. There was a NB02 gauge in the car that was useless. Since I replaced the MAF with the OEM AFM and installed the WB02 I have driven about 150 miles and I am pretty sure the AFR is nailed, 14.1 or 14.2 idle, steady state throttle driving at 3k RPM AFR is 13.9, WOT low 12s, maybe high 11s.
