Cylinder 1 misfire help 3rd gen 4runner

Hello everyone,
I have a 1997 Toyota 4runner sr5. Currently I'm having trouble with a cylinder 1 misfire. Starting Jan 2025 my mechanic friend did a head gasket on my vehicle along with underdog race headers and fuel injectors. A week after the job I got a cylinder 1 misfire. Here is what I've changed so far to fix the issue.
Spark plugs denso dual node
Ignition coil packs. Had denso had to buy ena ones off Amazon
NGK Spark plugs wires
Had to replace intake and a few vacuum lines
Did a compression test and got 150 on all 6 cylinders.
Did a leak down test on cylinder 1 and that was good.
Tested the shims of the valves with my friend and the valves are not tight and within spec.

My guess its like a ghost code or computer related. It runs well for the most part. Sometimes it'll idle low. When the code triggers I don't feel much when it happens. But it's getting annoying.

Any advice or other things it might be?
Let me know what y'all have heard

 

Did you swap the #1 injector to see if the misfire moves? Sounds like things would have changed if it was a plug/coil pack/wires.

 

I haven't tried that yet. If it moves then I'll know if it's that injector. I tested the ohms of injector 1,3, and 5 and they were all around 18 I think. I'll give an update when I do try that.

 

I'd bet injector also

 

How's your 4runner running? Did you figure it out? I have a similar issue with mine

 

Okay so update. I first was running premium gas and that solved the check engine for a bit. I just recently had time to switch injector 1 and 3 to see if it switches because my lower ball joint popped going into my driveway. So, I had to fix that first. I'll be driving it this weekend to see if it is the injector. My guess it is going to be the injector.

 

Who installed that lower ball joint? That's not normally how they pop. Someone failed on the install.

 

It was some shop where I live but the bolt on the ball joint just slipped off and stripped the threading somehow.
I installed new lower controls arms, ball joints, and an axle.

 

That sucks, there I good chance you ruined your CV axle (maybe not, nothing has to break for it to come out like that) and you can't get good new ones anymore.

If a shop did install it I'd warranty their work, I wouldn't trust them to do it again, but you should get refunded because that's not something that happens without improper installation if you used quality parts.

 

So the check engine light moved from p0301 to p0300. I deleted the code and it came back as p0303 which is the injector I switched. Going to buy a new injector and see if that does the job.