these are my old spark plugs that came with the car(i dont know how much km's they have):

(the oil is for a leak in the valve cover)















i have a b18a2 and it was runing fine, it pass emissions with no problem, no missfires but the spark plugs are like this, i think they look good but they have a orange color in the insulator, the electrode looks almost normal, but i was wondering, do you think i need to recalibrate my tps? i replaced them with denso u groove spark plugs and my idle is at 500-600rpm now(600-700rpm with nkgs).
The idle is lower but i think it has more power now, i checked the timing mark in the isulator of the new spark plugs and look pretty good.
any ideas??

 

NGK Spark Plugs USA

 

i started a thread thats stickied in the engine management/tuning thread that will be helpful