Is it legal for two minors to have sexual intercourse? (PC 261.5)

Sexual contact while under the age of 18 is not legal.

No. The real question is will a 17 year old actually be prosecuted for having sex with a 16 year old? That depends on numerous potential variables, including consent and the relationship between the minors involved. If you have a child facing charges of unlawful sex with a minor, call the experienced lawyers at Wallin & Klarich for assistance.