Yesterday I replaced the fuel pump on my Subaru Legacy 91' cuz it would not start. That fixed the problem. Now a new problem has sprung up. When attempting to quickly accelerate, the car refuses to respond. I mean flooring the accelerator results in nothing. I can still drive the car and get it up to 60km/h but I would be unable to pass someone. The RPM meter seems to get past 2.5 a little but quickly fall back down while the car gives the sound of an attemted acceleration. What could possiblly be the problem now?

Perhaps its in limp mode? Any CEL's coming on? Perhaps you got the wrong pump, or the connection is poor?