1997 GMC Yukon Q&A
1997 GMC Yukon Question: whats causing the p0306 code
Did you clear the code after repair? If so check compression and for a vacuum leak on or near # 6 cyl. Third cyl on pass. side. - pushrod
check the coil - your.mechanic
started rough idling out of the blue one morning.Fires right up and drives but rough. P0306 code.Engine light flashes when driving but is steady when idling. Changed spark plug from cyl 6 to 4. Sti...