How many miles on it? How long have you had the check engine light on for? 1-2 months? Longer? WHAT DTC(s) SPECIFICALLY p0300 , P0301-P0306. do not DRIVE IT IF THE mil IS FLASHING WHILE RUNNING! WILL CAUSE MORE DAMAGE. Inspect spark plugs (keep in cylinder order rear bank(firewall side from pass. to drivers side is 1-2-3- , front bank from pass. to drivers side is 4-5-6-. Carefully inspect each coil pack for heat damage and also keep in order. IF any of the coil packs have an excessive amount of what looks like rust build-up (light dry brown) or bluish-black hot spots on them (those may be harder to see unless moving around under light til at the right angle) suspect them as faulty. replace as needed after verifying.