This may be a bit long, so bear with me.

My current suspension setup is Function & Form Type I coilovers on all 4 corners (lowered maybe 1-1.5", I'm not exactly sure), and a bigger rear sway (I think the previous owner said it was a CTR sway). Front camber is ~-1.5 degrees, 1/32" toe out. Rear has some negative camber, and I'm not sure about the toe (haven't checked it yet, but it looks and feels darn close to stock).

Starting around 5-6 months ago, I started hearing a popping noise from my front left suspension. It was really hard to pinpoint a trigger, but it seemed to only happen driving over bumps. After poking around a bit myself and not finding anything, I took it to a shop for a diagnosis. They said the damper was on its way out.

After several months I got both replacement front dampers from Function & Form. The original coilovers were made for the Type-S (no EP version at the time), but since then F2 had updated their Type I dampers, and I got the updated ones for the EP. I shucked the springs and other hardware from the old dampers and put them on the new dampers. The retaining nut on top of the whole assembly was different, and there was a bit of a gap for the spring to slide up and down the damper between the top and bottom perches (only when the bottom perches were all the way at the bottom). Once I installed them however, it fit fine and everything felt secure. The old dampers used Type-S tie rod ends, so I swapped the stock EP tie rod ends back on with the new dampers.

After a test drive I heard a bunch of clunking/knocking, and upon examination I realized that the new damper brackets were only drilled for 14mm bolts and the OEM damper/knuckle bolts are 16mm. I purchased all new OEM bolts, drilled out the damper bracket holes, bolted it all up a week ago and it looked fine.

Now the original popping noise is back (front left only). In addition, both front assemblies will clunk/knock very loudly on large or sharp bumps in the road, and I can clearly feel it through the frame and chassis. (I've also noticed the steering deflects to the side sometimes when that happens, although this is the first time I've had a proper front end alignment, so I'm not sure if it's the clunking or just the alignment causing that.) Small/slow bumps will not cause any unusual noise, and bouncing the car myself won't cause any noise.

Any suggestions on what could be wrong?