2008 Toyota Tacoma Misfire code PO306

Question

My 2008 Toyota Tacoma has check enging code PO 306. It only misses when starting up in the morning after being driven the day before. It will miss with check enging light flashing and continue to miss until engine is shut off and restarted two or more times, then run fine after that! Truck will only miss after setting overnight 8 hrs, etc. Truck has only 17,000 miles and has been well maintained.

I have replaced all spark plugs, and ignition coil pack for cyl # 6, used fuel injection cleaner and checked mass air flow sensor. Problem still persists! Has anyone else experienced the same problems? Can You help?

Ps have read on-line that faulty head gaskets may be the cause of problem leaking antifreeze into cyl #6 after setting overnight?

Answer 1

It is more likely to be something else before head gasket, misfire has a lot of possible causes

see picture below of everything that needs to be checked.

you may have an injector issue, you can swap #1 with #6 and see if #1 will misfire.

You can also check compression min: is 145 psi and max is 189psi