2012 1.4T auto w/ 128,xxx miles. Started a couple weeks ago, very slight stutter and intermittent. Now, any time I put enough load on the engine to accelerate without downshifting, it stutters badly. If I stay on the gas, the CEL will flash for a minute or so. Used the scan tool w/ torque pro and got a pending misfire on cyl 1. Accelerating from a stop is ok as long as I keep rpms up above 2500 until I get to speed. This ONLY happens when the engine is completely warmed up. Its getting very annoying trying to merge/accelerate for lane change. Any ideas what to look for? I put in new spark plugs mid-summer and has been running perfect until this. I have always ran 91 octane, unless unavailable.