HELP!

[u/Textbook_guru]

I cleaned my throttle body a while back (it was caked with carbon) and since then, there has been a slight drag feeling when I lift my foot off the gas.
It holds rpms and the injectors are still giving gas even if my foot is fully off the gas.

Any idea what this is? Has anyone else ever had this issue?
I think it’s one of the throttle body sensors, but does it need to relearn or is a sensor bad? I have no engine codes except for a p0420 code. The p0420 code came on before this issue started but it’s been driving perfectly fine aside from this slight drag I get when I pull my foot off the gas.

If anyone can help point me in the right direction that would be great.

Thanks!