I know my camry has a broken exhaust (where the catalytic converter should be) but now it makes a really loud chugging noise, not all the time. Usually only when it's cold...today it was all the way warmed up but starting making the really loud "chugging" noise going down the freeway...didn't want to go faster than 60 mph. Could this be because of the cracked exhaust?

No not likely but would guess that catalytic converter is plugged, if you don't do something soon you can cause some damage to the engine. also with gas leak the computer does not function right because of the loss of back pressure from the exhaust system. MANY PEOPLE DON'T UNDERSTAND IF THE BACK PRESSURE IS WRONG THE ENGINE WILL NOT RUN right. The car can have a miss that you can't detect and that destroys the cat. So don't be surprised if you need a tune up and a top engine clean to make it run right. And if you live in California and are using gas with MTBE's it makes it even worse. So take it to a shop and they can use two things to test it. One is a infrared heat probe that will tell them if the cat is working or not and if the cat is plugged. the other is a gas analyzer. Also be aware if you have exhaust leaking it can get into the car and you can't smell the CO2 and if you have kids it has been prov-en that the CO2 will hurt children and older people as the CO@ level builds up in the blood and deprives the body of oxygen so
Please be careful with this issue, if the shop does not have a heat gun they can connect a vacuum gage up to see if the cat is plugged that way. hope this helps.

Could be if sucking air in throwing off fuel miture readings on oxygen sensors,