So last week when I did my tune-up on my car I took off what was left of the rusted out heat shield around my header and discovered a crack right where the oxygen sensor is. I'm pretty sure I've been riding around with it like that for a while being that its the stock header. My question is, how long would it be alright to drive it with it cracked?

I'm going to be getting a Megan 4-2-1 header once I pay my credit card off ( I dont have that much to pay off btw) and then once I pay the header off I'm getting a Megan cat-back exhaust so I can do my entire exhaust system in one shot.

Also my car hasnt thrown a CEL (would the crack near the oxygen sensor cause it to?), so I'm hoping it'll be cool for a little while until I get my replacement header.

it wont damage your car at all, it'll just be loud.

You're probably just gonna wanna get that fixed as soon as you can anyway. Good habit..