Do a Cylinder Drop Test at Idle. IF you have cylinders not running, then get one of these to listen to the injectors. [ http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_automotive-stethoscope-autocraft_10042652-p ] This will let you know if the injectors are firing.. Listen to the Tops of all six injectors.. the sound should be the Same on all Six.. If not, the silent ones are not firing.. COULD be a bad ECU driver circuit.. or bad wiring.. likely not the Injectors cauze they were just changed Do a compression Check.. Check the coils.. swap them around to the other cylinders to see if the defect follows the Coil Pack..