I recently started driving my 1995 Oldsmobile Cutlass supreme (3.1l) after a bit of a hiatus, and it started missing and developed a vibration at ~2000 rpm that stops ~2400 rpm. I replaced the spark plugs and the spark plug wires, and it started running smoother, but still misses and vibrates ~2000 rpm. Does anyone have any idea what could be causing this and what I can do about it? Thank you!