Zours were gone by December 2020, and unlike most discontinued candy there is a straight answer attached: the maker said so itself, gave a reason, and named what to buy instead.
What was actually said, and when
On 3 December 2020 the Mike and Ike account, answering a customer, confirmed that Sour-licious Zours "have been discontinued" — past tense — citing limited interest from retailers and consumers, and pointed at Mike and Ike Mega Mix Sour instead. That fixes the end at on or before that date. It does not fix the month, and we are not going to round it into one: a reply saying something has already happened is not an announcement that it just happened.
For the record on whose candy it was: Zours were a Mike and Ike line, made by Just Born of Bethlehem, Pennsylvania — the Peeps company. The full name on the box was Mike and Ike Sour-licious Zours, and the Zours trademark has been Just Born's since 1999.
The replacement, and how it differs
Mega Mix Sour is the manufacturer's own answer to "what do I buy instead", and we stock it. Same chewy body, same kitchen — which is more than most substitutions can claim.
It is not the same sweet, and the difference is the thing people actually miss. Zours carried a loose sour powder on the outside that came off on your fingers; Mega Mix Sour is sour through the chew rather than dusted on it. That was the specific complaint in the petition fans got up after the discontinuation, and it is worth knowing before you order.
The rest of the Mike and Ike range is here too, including Sour Watermelon and the Tropical Typhoon and Berry Blast mixes. If it was the sour hit you were after rather than Mike and Ike as a brand, our sour candy shelves go deeper than this page.