so im doing my X pipe install on a 2006 gt and im having issues so i was gunna finish it on my friends lift on thursday, is it safe to run my car on just headers till thursday or should i put the stock stuff back on??

 

I wouldnt do it much, the cold air can get up to the hot valves once the car stops, and then you got problems

 

Can you? yes. Hope you dont see any law enforcement
Should you? Agree with UCMC1775, not often or for long. But it will sound sweet. You will be heard for miles, so you wont even need to "see" the police, they will probably find you. And driving with now cats will be a LARGE fine.