Is this in general too loose? I have 16.5BB.

No Limit Hold'em Tournament T4,000/T8,000
Buy-in: $50+$50+$9 USD Hold'em No Limit
PokerStars
8 players

Stacks:
UTG - UTG (T308,246)
UTG+1 - UTG+1 (T252,646)
MP - MP (T292,591)
MP2 - MP2 (T227,010)
CO - CO (T307,167)
BTN - BTN (T390,229)
SB - SB (T342,767)
BB - Hero (T131,776)

Preflop: (T20,000, 8 players) Hero is BB with 4 4
2 folds, MP raises to T20,000, 3 folds, SB calls T16,000, Hero raises to T130,776 (all-in)

Nah seems fine. We def have FE here vs both players and theres 40k+ in dead money already in the middle.

I think it's a pretty okay squeeze spot under normal circumstances. However...

The buy-in of $50+$50+$9 would indicate it's a bounty tournament, which cuts our FE significantly. This makes it much closer - I think I'd just let the hand go. Also dependent on bounty size etc. obviously.

Reads on players would help, but you having the short stack in a bounty normally means people are more focused on you. The SB having 40+ bbs and flatting knowing that you have a stack size you're likely to shove with, would make me more inclined to just overcall the raise.

If I thought SB had been more passive, then I might jam, but without that read, you're the shortest stack at the table by far. In a bounty. With no mentioned reads on players. Costing you less than 10% of your stack and getting 4 to 1 preflop, and having a 2 to 1 STP ratio, which should make getting more chips easier if you hit a set.

All that info would have me me calling, but how the small blind has been playing is the most important factor

Perfect spot and candidate to squeeze with here.

First hand at a new table and you have 16bbs in the big blind with 44. Middle position 35bb stack 2.5x opens, small blind 40 bb stack just calls. You have 44 in the big blind with no reads on either player, and no reads on the table. And it's a bounty which should hurt your fold equity...

Far from perfect imo, but we may have different definitions of perfect