not a 1990 its a 1989 on 1990 Oldsmobile Cutlass Supreme

iHAVE POPPING OUT THE AIR INTAKE AND NO POWER ON A FLAT SERFACE GOES GOOD BUT UNDER A LOAD ON A HILL 26 MPH TOPS ??????

Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
1 answer 3 comments
Sounds like your Catalytic Converter may have gone bad, which can be problem on this vintage GM cars. They fail and plug up. Have a shop do a back pressure check. that will answer this question.

Best of Luck!
thanks dandd
crossed wires and o2 sencer just had this problem popping out the throddel body
our 1990 Cutlass acted the same way. It needed a new catalytic converter.