E4od issue

I’ve got a 91 f250 with the E4od and I the last 2 times I’ve drove it at about 65-70 mph and it’s been in Overdrive. All of a sudden I’ll lose a bit of power and it almost downshifts and then all of a sudden it’ll catch and lurch forward and be fixed fine and dandy. It threw a check engine light and immediately went right back off a second later. It doesn’t happen often but when it does it’s random and only has been on the freeway. The speedo floats around a little bit so I might check it on the rear differential and see if it fixes it but what might be some other issues?

I’ve got a 91 f250 with the E4od and I the last 2 times I’ve drove it at about 65-70 mph and it’s been in Overdrive. All of a sudden I’ll lose a bit of power and it almost downshifts and then all of a sudden it’ll catch and lurch forward and be fixed fine and dandy. It threw a check engine light and immediately went right back off a second later. It doesn’t happen often but when it does it’s random and only has been on the freeway. The speedo floats around a little bit so I might check it on the rear differential and see if it fixes it but what might be some other issues?