I have a 1992 Automatic EFI. I’ve had a high idle I can’t get rid of. Especially idles high in park or neutral. I want to get this fixed asap as my mpg sucks.

Anyone out there have success with fixing their high idle issues with IACV cleaning?
I saw a youtube video but dont want to attempt taking it apart until I at least get a new gasket for it.

replacements are super expensive. So any advice here would be great.