I was driving my truck to work a few days ago .When I stopped at the stop sign I had a rough idle . Sounded like it was hitting on seven cylinders . There is no smoke . Parked the truck for a day and got a P 1093 c code . I cleared the code and took it out again . Truck seemed to run fine . Next day back to work ran fine . Got off the freeway and it idled bad again . Got to work and idled smooth again . Stopped before going home rough idle . Checked codes and the P 1093 was back . Stopped again before my house idled smooth . Parked truck rough idle again . Never seen any smoke .So what are the thoughts and would a tech 2 tell me where to start looking ? Where could I get a tech 2 scanner ? I am using a OTC genysis 3.0 .