Longterm effect of not changing exhaust manifold?

[kingbiscuit]

I have had some noise from my exhaust manifold for quite some time now. The mechanic told me it needed to be changed but he didn't seem to put any urgency on the issue, so I have just left it because I have had other things to spend money on recently. Should I be worrying about my engine or anything else being affected by this? Also does this drastically affect performance?

 

[jpless]

I am not sure about the answer but I was wondering how many miles you had? I just replaced my exhaust system since somebody cut out my cat while i was parked at work. The new exhaust is substantially louder (faster, and better mpg!) so i'm not sure I would be able to notice a noise coming from my manifold if it starts to be a problem. Just trying to figure out when/if i should ever replace it milage-wise....