1991 Cadillac Deville with 4.9 L engine. 156,000 miles Has a miss in cylinders 1, 2, & 8. I replaced plugs and wires. Did a compression test and it has 165 psi on all cylinders. In park it sounds like it has a lot of power when I rev it up, but I can only runs good when in park but no power when in gear miss in cylinders 1, 2, 8 replaced MAP sensor.