The campaign to "redd up" Pittsburgh became official yesterday, as Mayor Bob O'Connor ordered building inspectors to enforce codes, raze buildings and tow abandoned cars, even if the law applies the brakes.

The campaign was welcomed on Tioga Street in Homewood, where a community group has been fighting the tide of debris lot by lot, but needs the city's help.

"If you change the environment, you change the behavior," said Dianne Swan, executive director of the Rosedale Block Cluster, as she stood in front of a trashed house with an abandoned Volkswagen Beetle in the back and the site of a September slaying in front.

Mr. O'Connor gathered the 72 employees of the Bureau of Building Inspection at their Downtown office to prepare them for a 16-week effort to improve the city's appearance in time for the Major League Baseball All-Star Game.

He made it clear that effort will go beyond Downtown and the North Shore, and isn't about banners and fresh paint.

Abandoned cars have to go, he said. Told that many cars sit rusting on properties for which the owner cannot be found, and that state law bars salvors from scrapping such cars, he urged the inspectors to be bold.

"Why don't we just take a picture of the car, tow it, so if we get sued, we can say, here's what it's worth?" Mr. O'Connor asked.

"Don't be afraid to make a mistake -- as long as it's not a Mercedes Benz. ... [If it's a] $200 car or less, get it out of there."

He said the administration may lobby state lawmakers to change laws to make it easier to remove and scrap cars left on abandoned lots.

Last year, the bureau cited 610 property owners for having abandoned vehicles and had 128 towed from private property, said Ron Graziano, chief of building inspection.

In Homewood, they're not keeping up. Ms. Swan said flatbeds pull into the community at night and leave junkers. The Beetle behind 7628 Tioga has a 1998 inspection sticker on its shattered front windshield.

The house at 7626 Tioga St. is one of 1,200 on the city's condemned buildings list, including 161 in the ward that includes Homewood and East Hills. The job of tearing it down hasn't yet been bid out, said Mr. Graziano.

The city's tentative budget includes $1.88 million for demolition, which would pay to raze 300 buildings. That would just keep pace with new condemnations.

Mr. O'Connor said he wants to get grants to increase the demolition budget. In the meantime, the bureau should tear down condemned buildings near schools. "Homeless people living there, drug dealers, we don't want that element near our kids," he said.

Property owners should be told to maintain their sidewalks and to paint over graffiti, he said, and should be fined if they don't heed warnings. The bureau sent out 300 graffiti notices last year, Mr. Graziano said.

Executing the mayor's orders in some tough neighborhoods could be challenging.

Senior Inspector Joseph F. Laffey told the mayor that someone recently "came after me with a baseball bat" while he was examining tumbledown homes. Inspectors agreed that in some neighborhoods, stripping plumbing and other valuable materials from empty houses is a cottage industry whose practitioners don't like competition.

Mr. O'Connor told Mr. Laffey to take police with him on his rounds. "You could be doing us a favor because that cop could bust those crackheads," he said.

Ms. Swan leads a troop of young people who clean 20 Homewood lots every day before fulfilling commercial landscaping contracts. They are hard-pressed to keep up with the litter.

She seconded the mayor's cleanup call.

"It's our community, and we're taking responsibility, but we need [the city] as a partner," she said. "You can't become a little municipality yourself."