Terrorist Faisal Shahzad bought inferior, and less expensive, materials to build his crude Times Square car bomb to avoid setting off alarms with law enforcement, NYPD Commissioner Ray Kelly said yesterday.

“He tried to lessen the explosive nature of the fertilizer that was used because he thought he would get a higher profile as he went to buy it,” The Wall Street Journal quoted Kelly as saying at a Washington, DC, think-tank meeting.

Kelly was asked about Shahzad after The Post reported exclusively that if the terrorist had used the right ingredients, the result would have been the deadliest domestic terror attack since 9/11.