big problem... please help... <exhaust related>

[araknid01]

i recently installed a new thermal catback exhaust system. i have changed nothing on the car but my exhaust... my car has always ran flawlessly..... now after the install. if i dont sit and let the car warm up to operating temp. and try to take off the car will stall out or start idling like ****. but if i just let it warm up its fine. please let me know whats going on... i know this cant be normal.. ive been tryin to find out some info on what could be wrong but i can find nothing... any help would be appreciated...

oh i tried resetting the ecu.... no luck

 

[Jebus[tuning]]

It helps to know what kind of car, wether it be 1g, 2g, or GVR4

 

[araknid01]

95tsi awd

 

[araknid01]

today the car did the same thing as i stated above.... but i have some good news... it threw a cel so maybe we can figure out what the deal is... the code is p0125.... any help is appreciated