It’s looking more and more like CBS’s revived “Jericho” will last only a few more weeks. In its second outing, the post-apocalypse drama slumped from its already-low debut, just months after CBS warned that for “Jericho” to warrant a third season, it would need to attract more viewers.

“Jericho” averaged a 2.0 rating among adults 18-49, according to Nielsen overnights, off 23 percent from a 2.6 for last week’s season-two premiere. “Jericho” placed second in the 10 p.m. timeslot, 0.1 ahead of ABC’s “Boston Legal.”

“Jericho” was famously revived last year for a seven-episode run following a campaign by rabid fans protesting the first-year show’s cancellation. But CBS Entertainment president Nina Tassler warned that unless numbers for the show improved, the show would not be back for season three.

So far this season, the two episodes are under the show’s full-year average for last season. Part of the problem may be the timeslot, which has been one of the weakest links on CBS’s schedule for several years now. Plus, “Jericho” aired much earlier last year, at 8 p.m. on Wednesdays.

Fox was first for the night among viewers 18-49 with an 11.2 average overnight rating and a 27 share. NBC was second at 3.3/8, CBS third at 2.0/5, Univision fourth at 1.6/4, ABC fifth at 1.5/4 and CW sixth at 1.0/3.
 
At 8 p.m. Fox led with a 10.5 for its first hour of “American Idol,” with NBC second with a 2.9 for its first half of “The Biggest Loser” and Univision and CBS tied for third at 2.1, Univision for “Al Diablo con los Guapos” and CBS for a repeat of “NCIS.” ABC was fourth with a 1.2 for an hour of “Just for Laughs” and CW sixth with a 0.8 for a “Reaper” rerun.
 
Fox led again at 9 p.m. with an 11.9 rating for its second hour of “Idol,” followed by NBC with a 3.8 for its second half of “Biggest Loser.” CBS was third with a 1.9 for “Big Brother,” Univision fourth with a 1.6 for “Pasion,” ABC fifth with a 1.5 average for “According to Jim” (1.6) and “Carpoolers” (1.4), and CW sixth with a 1.3 for “One Tree Hill,” though that show did rank third in the hour among the network’s target 18-34s.
 
NBC took the lead at 10 p.m. with a 3.3 for a repeat of “Law & Order: Special Victims Unit,” while CBS was second with a 2.0 for “Jericho.” ABC was third with a 1.9 for “Boston Legal” and Univision fourth with a 1.2 for “Aqui y Ahora.”
 
Fox also finished first for the night among households, with a 16.4 average overnight rating and a 25 share. NBC was second at 5.4/9, CBS third at 4.9/8, ABC fourth at 3.6/6, Univision fifth at 1.9/3 and CW sixth at 1.7/3.