My vehicle has been having a hesitation problem for some time now. i have taken it to several mechanics and have not found the problem after spending several thousand dollars. i took it to the local dealer (brown hyundai) in laredo tx and they point to the catalytic converters (3) and the oxygen sensors. i have had a mechanic remove the catalytic converts and tell me there is nothing wrong with the converters. the vehicle exhaust system reaches over 500 degrees. i have measured it with a heat gun. while i do not know what the proper temperature should be i know over 500 degrees is way to high. while i went to pick up my hyundai at the dealer he told me they had just had 2 other vehicles xg350's with the exact problem. if you go on line and read some of the codes they refer too "band 1 and bank 2 system too lean", this is a very common problem without an exact solution. i believe the code is p0174 and p0171. both the mechanics i have hired and the dealer have checked the list of possible problems which include: intake air leaks oxygen sensors ignition misfiring fuel injectors fuel pressure mass air flow sensor. *tr