This U1131 Code is very valuable for the car engineer fixing the car engineer. Do not drive the car if you find any problem in the car engine. When the car engine is tested and find any error in the car engine, then you can see the engine code on the engine code reader. The automobile engineer must not use wrong meaning of the code. Because, he knows that due to the wrong meaning of the code, the car engine may get more problem. So, you should be careful if you want to fix the car engine by yourself. You should have necessary expertise.