Running really rough

Do you have a 'check engine light'?

Yes, and it's on. The only codes that come up are for the evap system

stevenjeffress67 said:

Yes, and it's on.

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That's what I meant by having a CEL.

stevenjeffress67 said:

The only codes that come up are for the evap system

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Are you getting multiple codes for issues related to the evap system or just one?
I am certainly not an expert on the subject(s), but in my limited experience I have had some EVAP system leaks which have generated codes but none of them have ever had an effect on performance (for me).
I suppose it would be possible for you to have a leak in the vacuum line from the intake manifold or TB which provides vacuum for the EVAP system plumbing, & I can see where that would generate the CEL & also have a negative effect on your performance. Is it idling fast at all?

I am assuming that the reason you took the cat out was because you suspected a blockage was causing the rough running? How did you account for the post cat O2 sensor after you took the cat out?

How did the plugs that came out of it look?

The plugs looked really good actually. When it's in park and I hold the pedal down it will rev up and then stop after about 2 seconds and then it'll rev back up and it just repeats this cycle

stevenjeffress67 said:

When it's in park and I hold the pedal down it will rev up and then stop after about 2 seconds and then it'll rev back up and it just repeats this cycle

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I have read that the 3.7/4.7 are electronically more complex than the 3.9/5.2/5.9.
What you have described sounds maybe kind of sort of like what I have read about a bad throttle position sensor (TPS) but I would think that you would get a specific code on that.
Are you sure that the only code you are gettingis for the EVAP system?
Anyway, there is a check that can be done on both the TPS & the TPS circuit.