Misfire after spark plug change

Okay I have to admit right out of the gate that I got a Missfire code and neglected to note exactly which cylinders the code indicated.
After getting the missfire code I installed new spark plugs. I put in a new PCV valve and installed the oem copper plugs. The old plugs were clearly needing to be replaced and the gap was at least three times that of the new ones. I checked the new plugs before installing and the gap was good. I believe the misfire codes were p0301 and p0305 but sadly I'm not 100%
After installing the new plugs engine idles better and having unhooked the battery the code cleared. Drove truck that day and all seemed good. The next day in get the cel and missfire code again. This time I note the cylinders. P0305, and p0307.
Thinking I may need coils too I swap the coils for 5 and 7 with 1 and 3. Clear codes and drive until they return. Misfire doesn't change cylinders, still getting p0305 and p0307. So tomorrow I am going to replace the plugs for cylinders 5 and 7 again as well as clean the throttle body, check the air filter and add an injector cleaner through the fuel system. What I'd like to know, is are there any other obvious things I should look at checking while I'm doing these things? Anyone have ideas other than the things I've mentioned as to what could cause two cylinders right next to each other on drivers side to misfire?

 

Doesn't sound like the spark plugs are the problem since you have already changed them once.
how many miles on the car?

 

Truck has 168,xxx. I don't think it's the plugs either, but I have read a few posts other places that end with the new plugs being the problem. Since they're cheap and easy to change, I'm going to just check that box while I have the hood up

 

Watching this. Hope it can get resolved.

 

Are you sure they didn't get plugged in backwards or something?

Have to ask

 

You have taken really smart steps so far. Check the intake manifold for maybe looseness, a damaged gasket, or maybe even something pinched between it near those cylinders. Unmetered air sneaking in would cause a misfire.

 

Strange. If swapping plugs doesn’t fix it, I’d look at fuel injectors and intake manifold gaskets.

 

If the miss does not follow then I'd start looking for vacuum leaks like @johnnyskullface said, those will cause misfires.

 

It may be a good idea to replace air filter and clean your MAF sensor while you are cleaning up your throttle body.

Good luck!

 

@TX-TRD1stGEN would you clarify what you mean by 'plugged in backwards'?
I appreciate the suggestions @johnnyskullface I'll put those at the top of my list if today's steps don't solve it.
My post is part hoping one of the smarter more experienced members leads me to ideas and part for the benefit of others. This site has been so helpful to me since buying the truck about 6 months ago.
@FirstGenVol has a 'single stage paint correction' thread that took me from liking the used truck I bought to loving it in one day.
@empty_lord and @Professional Hand Model have posted tons of helpful info for those wanting to learn more about the 1st gen Tundra.
There are a lot more of you guys like @Darkness and several who I know I'm forgetting but I gotta say that guys like me appreciate the HELL out of what you share.

 

If the mis doesn’t move with coils or plugs I’d go compression test and if that’s good (should be), look into injectors. Vacuum leak, while possible, will rarely affect just 2 cylinders. If you have access to a scan tool with live data the long term and short term fuel trims should show a vacuum leak in the way of excessively high trims. (Ideally you want short and long to add up to -5-5%)

 

5-7 are next to each other too. Compression test would be my next go to just to make sure your not tossing money away, if you swapped wires by accident the engine would run horribly, so i doubt that’s a issue

 

Maybe a crack between the two pistons gasket?

 

That’s the very possibility I’d want to rule out before throwing parts at it

 

SOLVED!
...at least I think/hope.
After my efforts on Sunday, I still didn't have an answer. I called my buddy who recently got his master cert as a toyota tech. Brought it to him with the list of stuff I'd done already. At this point I was praying it was something I had carelessly done wrong because the list of cheap fix things that it could be was getting pretty short. I was pretty certain it hadn't jumped a tooth in timing because 1)It was only 2 cylinders misfiring
2)It didn't seem to misfire at higher RPM's while in park (not under load)
3) He had just helped me replace the belt about 4 months ago and we did tensioner and pulleys too

So I'm starting to dread the intake manifold gasket or worse as the answer.

He starts by checking my work, because ya know incompetent customers account for at least a third of their business
We determine that its not actually both 5 and 7 but only 7. He explained that often cheaper code readers will register both the misfiring cylinder and it's "buddy" cylinder.
We then swapped the injectors for 5 and 7. For those planning to pull injectors I suggest having replacement o-rings on hand. 3 of the 4 injectors that we pulled became damaged when we reinstalled them (rubber was just old and brittle)
Once we got all the injectors back in and checked for any leaking fuel, (another nice thing about his high end equipment was he could turn on the fuel pump with it and not have to start the truck) we start the truck and under load the misfire finally registers. It has moved to #5.
Shop didn't have injectors in stock, neither did any of the parts stores near me, so tonight I'll be installing the new one.
Hopefully that cures it. Stay tuned...

 

That's good news. Thanks for keeping us updated!

 

Don’t skimp on injectors! Inter motor is worth it. It’s rebranded oems. Cheap injectors can cause a whole other world of problems

 

Awesome feedback. I think many of these code threads get confusing due to ‘El Cheapo’ diagnostic tool/devices based on your buddies experienced feedback. What diagnostic tool did your buddy use?

Reman’d injectors come with 12 ports if you desire. They are a nice upgrade. I did all of mine last year for just over $300. Might be worthwhile for you.

Incompetent customers? Hahaha. I love it.

 

Update. A new injector was the answer. @Professional Hand Model I actually don't know the model or brand of device that he used. I asked about it and he said the dealership gives them one when they pass the master tech cert. I asked how much they go for and he said about $12,000 so I moved on
@empty_lord I did go with an inter motor injector, not cheap at about $140 but I agree it's not a part to skimp on. Interesting thing buddy mentioned is that the injectors very rarely go bad. In fact this was the first one he'd seen go bad on a 1st gen tundra.
At some point this summer I do plan to upgrade the injectors to the 12 hole remanded ones. They're sold by Dirty Deeds correct?

 

I can confirm in the 6 years at a Toyota dealer, we’ve never replaced 4.7l injectors. Rare to see them fail. But they definitely can.

 

I'd be interested in knowing this also. @empty_lord if you don't mind saying, do ya'll use the real version/setup of Techstream. Also, what other diagnostic OB2 due you personally use for basic checks, whether it be at work or personal, if you don't mind saying.

 

Yes. Dirty Deeds.

That High Dolla diagnostic tool is the key. I suspected it would be in the $6-12k range.