Yesterday, when I was rolling up to my Dad's house I smelled something funny. So jump out with the car on an looked underneath and I had a white smoke coming from my front exhaust tube assembly (the part that looks like a braided mesh material). Now, I had just ran the car pretty hard, should I be concerned about this. Could this be the reason my car acts funny and hesistates or is this normal.

 

It os possible that you had some road debris, namely plastic bag, get caught up on you pipe.

 

I looked for something like that and didn't see anything. Do you think that its something I shouldn't worry about? I took it to an exhaust shop about 3 months ago and they said I didn't have any leaks.

 

worry only if it persists.

 

That's the flex pipe, and it may need to be replaced, I'd pay attention to it and see if it persists... Usually road debris burns black...
As for the hesitation, is it when it warms up?

 

Yep. Normally when its warm, but it comes and goes. Sometimes it will hesitate and stall 3 or 4 times a week, sometimes just hesitation and then sometime I will go a week or 2 without any hesitation at all.

 

Hrmm... Mebbe knock sensor... I'd also check fuel filter and maybe injectors.

 

Replaced knock sensor and fuel filter. Need to check injectors, but I don't know how.