hey everyone. i have a 97 dodge caravan sport 3.3 v6. since ive gotten the van the check engine light has been on and throwing the p0171 code which is lean condition in bank one. would it be the upstream 02 sensor, seems to me it wouldnt be because the van runs the same when cold or warm and 02 sensors dont come into play untill the vans warmed up, at half throttle and more it hesitates/ lacks power, runs fine on the low end. ive checked for vac leakes, cleaned the throttle body. can anyone pinpoint my problem ive already put 600$ into the van and would rather fix the problem instread of everything thanks