285 isnt omg hot, but its at the edge, id say give it about 1/12 to 1/8th rich turn on the HSN and all should be good, unless your getting that temp only idleing.....then thats a bit warm. if you are then give the lsn about 1/4 turn rich and let it idle a minute. be sure to clear it out a bit by driving it around a bit, and then check your adjustment via temps. the NX 15 i have in my CT5 idles about 190 - 215 or so depending on conditions.
Timmahh