dankula's vert

ok my 91 vert s5 n/a is messin with my head. the check engine light is coming on after 10 - 15 min of running. the car then goes into limp mode. i no its not the omp because i replaced it. i know i didnt buy a defective omp because i spoke with the previos owner and he replaced it twice. i have heard you can damage the ecu by driving on a bad omp. this may have happened. but im not sure and i dont want to keep swaping parts. please help.