问:发动机运行粗糙和P0401 P0171和P0174代码。

试图诊断代码上面列出。测试了EGR对插或限制线。检查好了。将摊位发动机空转时,你盖EGR控制电磁发泄用手指。拉下废气循环阀和线条视觉检查。所有的好。所有电气检查EGR螺线管和DPFE OK。发现真空EGR阀保持EGR阀打开发动机运行。与真空规测试时你有5英寸汞在空闲时增加到18到20你压低加速器和滴回到5英寸当你释放加速器。这种情况即使卡车在公园和引擎正在运行。 I think this is causing engine to act like it has a large vacuum leak which I think would cause the P0171 and P0174. I don't know what is causing the EGR Solenoid to allow the vacuum to pass through and open EGR Valve. Any advice? Sincerely, Ron Zara
我的车有一个自动变速器。