Just replaced the the stock wires with NGK.....nice product. Of course....still stumbles.
Coil pack with be here in a day or so.

Tip for those changing parts to diagnose: do your homework because toyota parts vary in price up to 50.00 or more from auto store to dealer to internet. Many here have spent 100's to find out that the dang injector was the problem. Local auto stores had the wire set priced on the moon !!! I found ngk wires online for 27.00 shipped. Coil packs???? 40-75 bucks each in the stores.
Found online for 12.00......lol.....i guess it will work!! Ha ha.
Seriously.....toyota parts seem to be a centerpoint for price gouging so do your homework
And please, always finish your thread with what the issue was in the end. Many of us are reading these threads in hopes of gaining more info and knowledge.

 

Wow.....finally fixed the bumbling stumbling 4 runner !
Just threw on a new set of coil packs from Am autoparts and it runs like a dream!
Got to give props to Am.....ordered yesterday at 3pm....delivered for $40.00 total today at 5 pm.
with new silicone coil boots. You know....the ones that are $40 at the autoparts store....wink wink!
I got away cheap on this one not spending anymore than i had to in order to fix the problem.
i'll throw an ohm meter on the coils tomorrow and see if one jumps out as bad. The original code was for the number 5 cylinder misfire.
Hope this thread helps someone..... Kenny s

Ps...not having to do injectors.....priceless!

 

Congrats on getting it fixed thanks for posting the result

 

They all checked out the same at 1.3 cold and 1.4 warm after i put them in a toaster oven.
I suspected they would because the car only stumbled under a load. Always idled perfect.
Most of the issues were happening at 2000-2500 rpms or on slight inclines on the hwy.
Plugs were all fine.....none fouled..

 

I had a similar problem, turned out to be a split boot.