1998 Pontiac Bonneville Q&A

1998 Pontiac Bonneville Question: engine has a miss, only when car is going up hill

I've put plugs,wires, new coil pack, fuel pump and filter, gas tank completely flushed, gas cap, Car went in for service, ran good and still does, until it goes up hill. drove car about a week, after service, check engine light came on, and the miss started. -
Answer 1
what was the code for the light?? Roy -
Comment 1
oxygen sensor -
Answer 2
Ihave same problem except i have not replaced fuel pump ,it does not occurr all the time -