I noticed in my factory tune for a s/c 2.4L twin cam engine that GM has it wanting the afr at 13.50. Is there any way to change that to 14.70? Also, I have the high rpm tables and low rpm tables done in open loop and the car runs great, once it goes into closed loop, it will throw lean codes and run horrible. Is it because the pcm wants at 13.50 and it is set for 14.7?