chugging at idle and acceleration. Flashing CEL. Misfire help

[Quiero]

2007 v6 169k miles 4x4. Motor is all stock. I am the second owner and most of the maintenance history is documented. I took this truck on a 1300 mile road trip just 2 weeks ago.

I replaced the plugs (with OEM Denso part #s) about 3 months ago at 167k because I had no history on them. They were slightly out of gap tolerance but looked to be in mostly good shape. No evidence of bad mixture or anything. I believe the coils are factory/ have never been changed.

Today the truck started missing hard at a stop light. I pulled off and gave it some gas. CEL started flashing along with VSC OFF and another indicator that I do not recall. Thankfully I was less than a 1/2 mile from work so I limped it back. Motor load (AC on, reverse, etc) seems to make it miss more.

For fear of saving the catalytic converter I didnt want to do any more road testing.

I'm hoping my OBD reader will show it is just a coil? Guessing I should replace all of the coils if one is bad. I have had some VERY noisy injectors but I hear that is common for these motors. I thought it was an exhaust leak but this forum convinced me otherwise.

I'm very thankful that it happened so close to work and not on the 150 mile overlanding trip I have planned in a few months

 

[Quiero]

Bump. My OBD2 scanner died. New one is showing up today.

 

[Buckaroo]

Bump. My OBD2 scanner died. New one is showing up today.

Report all the codes when you get your new scanner. Don't erase anything yet. If possible, don't start replacing things until you confirm the cause. Doubtful that code alone will do it - could be lots of things.

Buckaroo

 

[Quiero]

Report all the codes when you get your new scanner. Don't erase anything yet. If possible, don't start replacing things until you confirm the cause. Doubtful that code alone will do it - could be lots of things.

Buckaroo

P0305 Cyl 5 misfire.

My truck is an '07 that has been well maintained its entire life. Most searches lead me to HG? :Cry:

I just changed the plugs a few months back. Perhaps its bad plug? Hoping its that or a coil/injector

 

[Quiero]

quick update:

#5 is easy to get to so I pulled the coil. Boot is cracked about an inch. :high5:

 

[djpope09]

P0305 Cyl 5 misfire.

My truck is an '07 that has been well maintained its entire life. Most searches lead me to HG? :Cry:

I just changed the plugs a few months back. Perhaps its bad plug? Hoping its that or a coil/injector

Typically a misfire resulting from a failed headgasket is because you are getting coolant in the cylinder. When it happened to mine, it would only misfire at startup because coolant was leaking into one of the cylinders after shutting off the engine. The easiest way to confirm this is to check the coolant level. Glad you figured it out and it was just an ignition coil. So much less work/money.

 

[Quiero]

Road test went well with a new coil! :bounce:

On an unrelated note I test drove GX 460 today... man those things are nice

 

[Buckaroo]

Glad it worked out. For the future, would have suggested swapping the coil to another cylinder and seeing if the misfire followed before investing in a new coil. You could have also swapped the plug to a third cylinder and see if the miss followed that one. Finally, you can buy just a boot on Rockauto for $3-4 rather than replacing the whole coil.

Buckaroo

 

[Quiero]

Glad it worked out. For the future, would have suggested swapping the coil to another cylinder and seeing if the misfire followed before investing in a new coil. You could have also swapped the plug to a third cylinder and see if the miss followed that one. Finally, you can buy just a boot on Rockauto for $3-4 rather than replacing the whole coil.

Buckaroo

Appreciate it, thanks! The torn boot was obvious on removal, so I figured that had to be it.

I did not know the boots were replaceable, but I also have a road trip this weekend and needed to get it up and running quickly.

For anyone who comes across this on google, dont go too deep into the head gasket rabbit hole if you have a later '06 or newer. I've found virtually all of the misfire forum posts on pre '06 to revolve around the HG, and none after.