Gas Recirculation Valve (egr Valve) Problems of Hyundai XG350

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.

See all problems of the 2003 Hyundai XG350 🔎.