my car has 94xxx miles on it. all stock with a koyo radiator and a cat-back. when car starts warming up i see white smoke coming from the driver side and then theres this sour smell also coming from somewhere when driving. theres also white smoke coming out where my y-pipe is at.. any ideas?

 

Possibly a coolant leak, and the coolant is getting burned and giving off the smoke/smell. Burning coolant has a pretty distinct smell.

I'd start by checking the small coolant hose coming off the back of the waterpump housing and the coolant lines to the turbos. Also could be the coolant hose from the rear iron to the throttle body. You can look at the FSM diagrams for a better idea of where they're located.

 

Check the turbo coolant hoses.