hello everybody

i need some one to explane the AFR to me , coz i searched and foud that the 17 is lean and the 10 is rich!!

i have afr
14.7 cruse + idle
11.6 full throtle

and when my headers break down the AFR goes up to 18 and after that give me error!!!!

can anybody explan what happened to me !!!

and what mods do i have all in the signature