Check engine light comes on and flashes,the loses a little power ,

do NOT drive it with the CEL light flashing/blinking,PERIOD! you have a misfire and are dumping raw fuel down the exhaust manifold and will destroy or have destroyed the converter(s)QUICKLY...TOW TO A SHOP!

Have the Nissan towed to a shop and have an engine diagnostic done to determine the reason the Check Engine Light is flashing. Once you've determined the source of the problem you can have the car repaired.

Just call me on monday morning and I can get you right in and we will figure it out for you 317-248-0800 ask for Tom.