hi i'm new here plus i'm also owner of sx8 too ! izit you got orange light came out while driving half way,and the rpm going up and down when u stop?
have you get wat is the problem of it ? im facing this problem b4 about 2 year ago, but i'm not sure your problem same with mine o not, so i just to share with you my experience,if u haven solve the problem.
after i got this problem,i went to HSC for checking,they diagnose that my car duno which part of air-flow controller got problem and need to replace it.The technician from HSC said it is ok not to fix this problem, but when time pass by the FC of my car will increase due to the problem,so i decide to fix it.It cost me about RM600 to replace the part if i not mistaken, and til now my car normal again.