F512M Engine Issue

1995 F512M experiencing intermitant, but very brief (half to 1 second) losses of power (as if one or more of the cylinders were momentarily shut down) during regular driving. occurance not frequent (once or twice during a 1 to 2 hour drive) and the "check engine light" flashes when that happens. Similar problems had occured before with much more frequency and severity (once every 10 to 15 minutes with sudden drops in RPM) so replaced all sensors (oxygen and temp) and spark plugs, after which big improvement and car runs like a dream normaly, other than the occasional gremlin mentioned above. dealer checked computer and all electrical connections which are normal. any idea/experience as to where the bug might be??? thx

 

thx guys