1997 Oldsmobile 88 6 cyl Automatic 97000 miles
Check engine light came on and flashes. Had Autozone check for codes and came back with P0300 error code.
Replaced spark plugs spark plug wire set. Car starts but still has Vibration issue. Checked coil pack by using timing light at each spark plug wire and found coil pack 1 & 4 not firing. Replaced coil pack and problem still exists. Had all old codes cleared and light came on again with same error code P0300. Where would you suggest I check next?
Lost up ****creek without a paddle.