yeah guys your right it has nothing to do with me changing my gas just bad coincedence i guess.i went to see a mechanic and got my engine diagnostic test it seems that i need 2 knock sensors,gaskets,and some vacuum hoses are loose so that may be the problem thats causing smoke from my exhaust.The knock sensors are expensive though cost about $158 a piece plus with labor cost they quoted me to fix is about $500-$600 dollars.To me it seems like good deal what do u guys think? Thanks alot for the replies guys u were very helpful.