So my buddy has a 2001 escape. It has a shudder at 1k rpm in park and neutral. It's not nearly as noticeable in drive. I scanned it for codes and there isn't one. Ran a power balance on ids and it's straight. Doesn't miss during the shudder either. Has all new coils and plugs. I cleaned IAC. MAF. Ran sea foam through the engine. And there is Lucas oil conditioner in the oil and Lucan fuel injector cleaner in the gas. It runs amazing other than that shudder. What could it be ? So frustrated.

 

Sounds like the beginning of a COP failing. Idle is where you first notice it in my experience.
The sad part is that until the CEL stays on, the code won't be read by the scanner.