Placement of healing caps on implants on day 16 post op, is this a good idea?

If Healing caps are not placed right away at the time of implant surgery, it should be delayed for atleast one month healing , preferably longer at 2-3 weeks post implant placement , implants are not as stable and tight as the time of placement. This is just normal part of bone healing around implants. removing cover screws and tightening healing caps could actually loosen implants and compromise healing specially in soft bone So I would wait in your case, the symptoms you are experiencing should be dealt with Asap good luck 

One stage healing caps should only be placed at time of surgery.Exposure of implants too soon and the torque placed on the implants during the critical first 4-6 weeks can actually interfere with proper osseointegration (bonding of new bone to your implant).I would wait and be on the proactive side before placing the healing caps.As far as the swelling and lesions you describe, I would visit your dentist or oral surgeon to rule out allergies and /or possible infections.

I prefer to either place healing caps at the time of  implant surgery, or wait 2-3 months, depending on the upper or lower.  We place the implant completely under the gums whenever there is a situation that might inhibit healing.  With ideal conditions, we place the healing cap at the time of implant placement.  If there is any swelling or complications, those should be dealt with first before doing additional surgery.  It soulds like you are having compicatons that sould be dealt with prio to placement of healing caps.