What about tempering of throttle valve of Dongfeng Xiaokang gas refueling door?

Dongfeng xiaokang gas refueling door throttle for inspection and maintenance. According to relevant information, if the engine timing is incorrect, it is necessary to check the timing. The throttle valve is damaged or the exhaust system is blocked. The three-way catalyst is blocked and needs to be checked. Check what is analyzed when you are free.