what causes check engine light to blink awhile then stay on

A check engine light will blink when the engine is misfiring badly enough to cause catalytic converter damage

the 2001 Continental doesnt have "wires" on it, you just had the plugs changed...if they charged you for wires, you got ripped off, and they probably didnt use correct plugs either. The engine wants Motorcraft plugs, and wants them torqued to 13 foot-pounds if im not mistaken. If you went somewhere and they put Bosch plugs in or something, it will start misfiring, and check engine light could flash again, it has 8 coil packs, it does not have wires...the coil packs are around $40-50/per cylinder on this car...you'd remember paying for 8 of those, and you probably got ripped off if you purchased 8 new ones as they should be replaced one at a time, typically...unless you got a lot of $