Need input - Codes and Check Engine Light

Hello All,

Ok so recently I have had an issue crop up.

Car:
91LX AOD. 151k mi. Everything is stock except a 190lph fuel pump (which was installed after I was having the issue below).

Codes:
First round got a 13 KOEO and 13 KOER. ( I think this one had to do with RPM can not reach lower limit. My tac is stck at 4k. Does this have something to do with it?)
The second round I think it was the code where needs to learn the idle. (somehow I may have reset the computer.)

Issue:
My "Check Engine" light flashes occationally. Seems to pop on more so around
70ish mph. Really no rhyme or reason. Based on the history above, does anyone have any ideas why this is happening?

TIA
Matt

Hey Jricker,

Thanks for the reply. I actually have no idea what the car is idling at cause of my stupid tac is stuck at 4k. I'll look into that idle some how. What do you think about the check engine light flickering? Could it be a short?

Thanks again,
Matt

TTT