What could be the problem? (Audio clips attached)

^^^When accelerating under load, sometimes my car sounds like this. In other words, it’s normal. (I was driving through a tunnel in this clip that’s why it sounds the way it does.)

^^^Other times when accelerating under load, it sounds like this. It will rev up to 4000 rpms with a slight choking sound while it’s getting there and then get stuck like it’s misfiring/hesitating before it finally downshifts.

What could the issue be? Also why does it only do this SOMETIMES?

Both audio clips are from accelerating at 90% throttle.

Already replaced fuel and air filters, EGR valve, all o2 sensors, fuel injectors, TPS, Throttle cable, Fuel pressure regulator, MAF sensor, did plugs, wires, coil pack and ran cataclean through gas tank.

No codes present.

From the sound of it, I doubt it’s a transmission issue since the car sounds like it’s misfiring, but the shifting is delayed. However, it is an AT and the fluid is at the correct level and has been properly serviced

Are you going uphill on the second clip? when it is misfiring. thet decreases power but you still have the throttle open so it delays the upshift. An increased load on the engine can cause a misfire if something, like plugs , for example are marginal.

Both recordings were on flat ground accelerating hard from already moving

You’re saying a misfire under heavy load is normal?

No, I am saying that if something is marginal, it will act up at heavy load first.

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The engine tone in each clip is identical. If the engine had a misfire it would sound different and take 30 seconds or more to develop enough speed to up shift, not up shift briskly as shown in the audio clip.

If you want consistent performance, switch off the air conditioning or floor the accelerator to disengage the A/C clutch.

In the 2nd clip the engine is stumbling you have to turn the volume way up because it’s hard to hear

Are there no pending codes either?

There aren’t any pending codes

If you check my latest post i posted an audio clip on the noise the engines making