2005 Chrysler town & country 3.8 brake failure

So here is a funny scenario. I was changing the oxygen sensors pre-cat and post cat. Once I finish the job and I turned on the vehicle the minivan did not want to stop the brakes were very very hard plus the minivan had a high idle. I took the minivan for test drive and the van did not want to stop on the dime What did I do wrong what it’s happening what am I overlooking thank you guys

plug the brake booster into its vacuum source

Cheryl thanks you were dead on. That’s what happens when you don’t work on cars everyday. I owe you. Thanks again.

We have all done something similar.