Chirping Sable

While driving 30 plus mph, in my 2002 Sable with the windows open, I hear a chirping sound that seems to fade in and out. It does not do it until the car has warmed up. My car failed inspection with a p1400. The service engine light is also on. I feel like this noise could be a vacuum leak. Does anyone know what this might be or what I could do to find it?

dpfe sensor passenger side back of intake on firewall.controls egr vacuum it can be checked but good chance its the problem.good luck
dont think it would chirp thats probaly something else like hub bearing brakes ect

I finally had the car fixed by a ford dealer. You were correct. It was the dpfe senser. It also passed inspection. Sorry It took so long for me to respond and get the car repaired. I need to rely more on and trust this new source for information. Thanks again