HI ALL NEW TO THE FORUM HAVIN TROUBLE WITH MY 1995 WRX IMPORT THE CAR IDLES FINE AN NO ENGINE CHECK LIGHT THEN WHEN I FLOOR IT SHE PULLS TO 5 THOUSAND RPM THE CAR JUDDERS AN SPLUTTERS THEN ENGINE CHECK LIGHT COMES BUT DOESNT SEEM TO BE IN LIMP MODE STILL PULLS LIKE ATRAIN TILL 5 THOUSAND RPM THEN JUDDERING AN HELP BE MUCH APPRECIATED!!!!!!!!!!!!!!!!!!!!!!

 

Over boost is usually very sudden and cuts all power until you go off the throttle then back on. Where as if it missing it would be more juddery like you said. I would think both would temporarily flash the CEL.