I have a 2000 seville sts, started car no issues, drove to store 15-20 minutes, got back in started car and ck eng light flashing.
proceeded to pull over turn off and restart, still flashing.
Drove 25-30 minutes at highway speed, light went off then back on. Now idle is rough.
Scanned at a-zone, po306 came up.
changed plugs and boots, actually seems worse,
Can anyone give me some diagnostic steps other than parts replacement, in order to fix this.
Wednesday, December 19th, 2012 AT 10:57 PM