2011 GMC Acadia Denali p0300 and p0306

Question

I replaced all the plugs and moved number 6 coil to number 1 and still have the same codes , it idles rough and cel flashes .. it did not change anything ..there is oil in the air duct tube. And the throttle body has oil and the butterfly plate. What is my next step ?

Answer 1

HI there,

I would check the compression on #6 cylinder. If you have oil in the air duct it indicates possible blow by. Meaning the oil is getting past the rings and getting sucked in through the throttle. Also, check your pcv valve. it could contribute to the oil problem. You could also have a bad fuel injector on #6. Check the wiring to the ignition coil as well. You have to make sure you are actually getting spark in #6

Answer 2

dirty injectors. bad spark plugs .bad fuel pressure. dirty air and fuel  filter .