when i turn on the car it sqeekes and it is worse when i turn on the ac well i was on vacation and i took it to the shop and they said it was normal , well 2 days later it now back fireing all i got is a exhaste
take it to the guy that did your exhaust and tell him to fix it.. tell him it was fine before you fucked with it.. no excuses.. you might have an exhaust leak. ALSO the squeeking might be from a poor welding job.. maybe one of the flanges is loose.
When i talked to a guy down at the dealership he told me that exhausts dont typically void the warranty because they are after the combustion process. But if it is the problem it could so you might be better off taking it back to the person that installed the exhaust first.