So I've been experiencing this since I bought my IS-F from a former owner. This is a US spec vehicle in the states. I swapped out most of the old OEM suspension components to;

- All ball joints (lower and upper)
- SPC upper and rear lower adjustable ball joints and camber arms
- Tein H Techs
- Tokico HP Blue struts
- Moog front and rear sway bar bushings
- Beck/Arnley front and rear end links
- Proforged front lower ball joints
- Front upper control arm bushings are still stock (the two on the wishbone)
- RR Racing engine mounts (OEM busted)
- RR Racing USRS LCA bushings (OEM busted/leaking)
- Replaced all OEM transmission mount components with new OEM components (OEM mount was tired and compressed by a few millimeters)

The knock can be heard and felt when turning the wheel at low speeds when entering an intersection or exiting a parking lot for an example. I also get peddle knock when going over bumps that I could feel on the gas peddle. Any insights of what I may have missed would be welcomed. Maybe something with the steering column itself?

(posted through Android device)

 

Is this before and after you changed any of the suspension components?

 

The knock/vibration was there before swapping suspension components. Main reason I swapped a lot of parts out due to it being the original OEM at 151K miles and the front driver side strut was leaking. Now, there is additional knocking after I had replaced those suspension components when driving over uneven/bumpy roads and that can mainly be felt in the gas pedal. Update on suspension component list swap outs above in original post that I left out before.