i have a beautiful 2011 G37XS, added a Stillen exhAUST. New brakes< Michelin sport 4's, LOVE it. ive had a reoccurring check engine light,then it would go away. thought maybe cheap gas. only use premium. Now i have 2 codes, P0725 and P0106. I cant afford an infinty dealer> f someone has been through this please help. it runs fine< the only thing it does is die after start, and only occasionally. if a qualifiedd person knows wHAT i SHOULD DO, please help! thx