My van failed the 25 mph test with high NOX. The tech said it was most likely the EGR valve. So I run the engine, put a vacuum pump on the valve and I cannot pull a vacuum.. I manualy press in the diaphram and the engine stops. With the EGR off the engine, mouth vacuum pulls in the diaphram. There is only a single vac nipple, and no electronics on the valve.
Although there are two smaller holes on the EGR, there are no matching holes on the engine and the gasket has only two large holes, so the small holes are blocked off. . The EGR is same as ACDelco 214-5073. Can this be a back pressure valve? Apparently there is no check except to replace at $50+.
The same thing happened 2 years ago and it turned out to be a bad oxygen sensor. That was probably less than 500 miles ago. Can it happen again?
Thanks for your advice.
Slowpoke.
Although there are two smaller holes on the EGR, there are no matching holes on the engine and the gasket has only two large holes, so the small holes are blocked off. . The EGR is same as ACDelco 214-5073. Can this be a back pressure valve? Apparently there is no check except to replace at $50+.
The same thing happened 2 years ago and it turned out to be a bad oxygen sensor. That was probably less than 500 miles ago. Can it happen again?
Thanks for your advice.
Slowpoke.