For about a year now everytime she sits in traffic for a bit, I get an intermitent miss... especialy if I have the A/C on. After stopped for a bit upon initial acceleration she misses until she rolls a bit. Fuel pressure good (new pump), new plugs cap and rotor about a year ago. I always put in High test or mid grade. This morning I was low on cash so I got the cheapest gas. I drove to work... and not one miss. I drove back in about 100* weather in traffic... and not one miss. What happened? I think I read lower octane means the gas will ignite easier... does this imply that I have an ignition issue?