I may have confused you, mentioning AHC. AHC (AKA: Active height control), which is hydraulic suspension.
But it is was unclear, what model you have.
You asking "So the AHC is possibly not working ? " Implies you have AHC. AHC is in all LX's 470 & 570 if not removed by owner Only some (most) 2006 & 2007 Land Cruisers have AHC, no other years in USA models. So indication are. After going back and re-reading every post of yours, in this thread. You've a stock 03LX w/176k miles, with Ko2.
It was suggested in post #2. You, add vehicle info to signature line. This way, it's known to all at a glance. What make, model, miles and configured (stock or build). This avoid a lot of confusion.
Best parts, are almost always: OEM (Original Equipment Manufacture) form Toyota.
Stabilizers sways bars, rarely need replacing in a stock configuration. I do find, the more miles the more they're bent (settled-in). But typically I only replace if eyelet for link(s) rusted out badly. You'll find many threads on which parts (links, cushions, bushing, retaining washers and bolts) and how to change.
You should be able to make sweeping turns on ramps or open HWY mountain curves. Without the need to give steering wheel those little correction, associated with body roll. A properly set-up stock LC or LX, will hug the curves. Just like the day it roll out of the factory, it's so sweet!.