I have another issue with the car. I replaced the two belts on the front main pulleys and made sure they were tight. Then an aftermarket oil pressure gauge line was rubbing on them and it got oil all over them. I have the alternator tightened as tight as it will go and the belts are still loose. Do I need to replace them again? They were brand new

 

If the belts were tight before the oil leak, and now they're kinda gummy and loose... Yep. Replace them. Belts suck up oil and get gummy, that's why you have to replace a timing belt if it gets even a small amount of oil on it.