2015 P0306 code for #6 misfire

[Inferno PRO]

2015 with 63K miles and idle's real rough all of a sudden. We have had a huge temperature drop over the last few days and I haven't driven it that much. The truck gave me the check engine light and P0306. Surely it's not a blown head gasket. Any other 5th Gen 4Runners with the same issue? After searching all I can find is 4th Gen's and older.

I just replaced the battery tonight and it's still hesitating, idling like a sewing machine. Tomorrow I'll pull the #6 coil pack and see if theres any obvious signs.

 

[philsey]

Better check for rodents.

 

[wfo9]

10 bucks on Rodents, injector harness...

 

[jrandom]

Agree with the first two consensus...

 

[northcoast]

Agree with the first two consensus...

Holy hell, is that real?

 

[jrandom]

Holy hell, is that real?

Image search “rodents in engines” or similar. I have had three cases of rodents, two mice and one pack rat, chewing up my wiring/engine compartment over the years, always when visiting family in backwoods Idaho. My sister-in-law had her 2015 Subaru Impreza nuked when she left it at the trail head for two days, she came back and it wouldn’t run smooth or steer proper, $4500 later a new full engine harness, she sold it for a Crosstrek. I now leave my hood cracked and put magic tree pine air fresheners in the engine compartment, knock-on-wood no issues to date.

 

[Inferno PRO]

Rat/mouse it is

After switching the #6 and #3 ignition coils only to have the same code I decided to search a bit deeper. If I can get the pictures to load you’ll be able to tell that a mouse was the culprit of some chewed wires.

 

[Inferno PRO]

Another view.

 

[bamma]

Another view.

Your comprehensive insurance should cover the repair. Unfortunately, this is a common occurance. Honda sells rodent proof tape for anyone looking to prevent this.

 

[EddieV4runnin]

After switching the #6 and #3 ignition coils only to have the same code I decided to search a bit deeper. If I can get the pictures to load you’ll be able to tell that a mouse was the culprit of some chewed wires.

It’s not hard to find a new connector at your local parts store and replace it yourself, if you’re looking to save some money. There’s a lot information on here on how to move the intake if you search. It’ll should take you a couple of hours to get it done. Best of luck to you :hug:

 

[lj4r]

I got the same code on our 2010 SR5 (v6 obviously). Truck had been running perfectly, and then all at once, it ran horribly and through the P0306 code. I pulled the coil on Cylinder 6. It had signs of rust and gunk. I pulled the spark plug and it was black. I cleaned off the coil best I could. Tried to wipe out the spark plug hole and then cleaned up the spark plug. I had purchased a new coil from Toyota but I got the wrong coil. It was for a 2010 Tundra with the V6. The coil was too large to fit in the spark plug access hole. I put the Plug 6 coil on Plug 4 and put the Plug 4 coil on Plug 6. started it up and it ran perfectly. Cleared the code and it runs like new. Hopefully, Toyota will swap the coil for a new one. I noted that the coil on Plug 6 had a slightly larger than hairline crack down about 80% of the length of the coil.

I had done a cleaning of the engine bay and maybe water got through the coil seal and sat in the plug access hole. I thought that it would have evaporated with the heat of the engine. The engine bay, and the rest of the truck was incredibly filthy when I got it. (this 4runner had been stolen and run through the desert, either running drugs, it was covered in pot when I got it or those without passports (illegal aliens) across the border.

Hopefully we get it back from the paint shop this week. Thanks again for this great Forum. Tons of info. Phil