91' 5 speed LB9. Been in storage for 5 years. (Dry heated garage). Anyways car runs great except once in a while at W.O.T when motor is around 4000rpm, it just sits at that speed with no acceleration doesn't miss stays smooth but just hovers at 4000 as if an invisible man was holding the car back at constant speed. It only happens about half the time and only in 3rd to 5th gears. I hooked a Genisys scanner to it and recorded it happening. The only thing that popped out was EGR stays at 0% regardless of gear, throttle,rpm. I also recorded it when it pulled strong to 5100 but the EGR was still 0% all the way thru on playback. It also says "lean" when played back regardless if it pulls good or does the 38-4200stallthing. The only other thing scanner revealed was oil temp sensor is buggered cuz it always reads -40c. Would the screwed EGR valve cause a lean cond and the intermittant no accelleration deal? Everything else was within normal parameters on the scanner. No check engine light ever, new fuel filter. Maybe the fuel pump is dying? Can any of you gurus help?