Any mechanics that can help diagnose this?

I have a 2011 Prius. A month or so ago I got a P0301 code and replaced the spark plugs and ignition modules. It ran fine until today when it started misfiring again and again I have a P0301 code. I’ve also noticed that while in Park with the gas to the floor the RPMs rise and fall while my foot stays hard down. I also noticed an ethylene smell in the cabin when it started misfiring. Also, starting from a stop it misfires a bit, but once up to speed it’s fine. Before I start going to the next thing I can think of, which is to clean the intake manifold and EGR valve, do you think that would even be the issue? If not, then what?

Edit: it only misfires for a few seconds before going quiet again, even just sitting in park

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SubstantialKick · 36-40, M

How about your coil packs? That's the next thing I would consider.

Zaphod42 · 51-55, M

I replaced those with the plugs. I guess they could have gone bad already…Amazon parts 🤷‍♂️ @SubstantialKick

SubstantialKick · 36-40, M

@Zaphod42 Amazon? Yeah, I would recommend an actual auto parts franchise like O'Reillys or Autozone.

Zaphod42 · 51-55, M

@SubstantialKick yeah, I’m about to walk over to oreillys for replacement coil packs…hoping that does the trick

uncalled4 · 56-60, M

@Zaphod42 Sometimes, you have to go OEM or the computer no likey.

Zaphod42 · 51-55, M

@uncalled4 Yeah, learning that, lol. Just got back from the parts store…unfortunately they only had two coil packs, but since it was originally just cylinder 1 and just now #2 also, I’ll replace those two and see what happens.

uncalled4 · 56-60, M

@Zaphod42 I had to put 2 alternators in my Acura before I got an OEM. Turns out I didn't even need to do THAT, because bearings had seized in the harmonic balance, which I found out is not unheard of in the 2.5 engine(old Vigor model), so the belt was spinning but the balance was frozen. Eek.