hokay. so i just got myself an 02 wrx wagon. it has a catback exhaust on it. it has a horrible bucking and stumbling problem in every gear. when you stab the throttle it burbles and doesnt rev right away. the cel flashes and pulled code p0171. when you baby it is drives somewhat normal. my coworker and i pulled a spark plug today and it was white which indicated it was running lean. we also cleaned the maf sensor as well. checked for vacuum leaks and stuff. next up is the 02 sensor in the dp, going to replace that and see where i am at.
does anyone have any intel on what could be causing this?