I'm not to familiar with them i would like to know what can they do or not do and will it be usefull to have.. it will be goin on my beater turbo 2 haha..

 

Yea u would def need one...I put a new one on as soon as i got my car and it ran a lil better.

 

what has it done for you is it tuneable or somthing..or is it like a plug in and it does all the work..

 

A wideband O2 sensor just gives you a more accurate reading of how rich/lean your engine is running
you use it to ASSIST in tuning so you know what you're working with

narrow band O2 sensors (stock) are only accurate when the reading is very close to 14.whaatever ratio is ideal for emissions.