whats causing the p0306 code on 1997 GMC Yukon

replaced rotor cap plugs wires o2sensors mass airflow sensor and still getting code p0306 and it has a distributor and a throttle body, so what now

by in Placerville, CA on December 08, 2012
Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
2 answers 1 comment
ANSWER by , December 09, 2012
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.
ANSWER by , December 09, 2012
check the coil
COMMENT by , December 09, 2012
Only one coil for all cylinders. Should not set po306.