Does amox-clav contain sulfa?

No.

Amoxicillin and Clavulanate
Generic Name: amoxicillin and clavulanate potassium
Brand Names: Augmentin, Augmentin ES-600, Augmentin XR

Amoxicillin is an antibiotic that belongs to a group of drugs called penicillins.

Clavulanate potassium is a form of clavulanic acid, which is similar to penicillin. Clavulanate potassium fights bacteria that is often resistant to penicillins and other antibiotics.