Is the DPFE System affected by heat.?

Question

I have a 1997 E-150 Cargo van, V-6 4.2 ltr. I got a code 1401, after a major back-fire, which blew out the catalytic converter, and the engine over heated, as a result I had/have a blown head gasket.. So after the van cooled down, oil and water were replaced to the correct level, and the exhaust repaired, this code popped up.. The head gasket has NOT been repaired yet, but the engine is running fairly well. It has only a minor engine misfire on cylinder #6, when it is cold, and it blows a small amount of gray smoke, when the engine is cold, but that clears up at normal operating temperature. It also blows coolant/water, out the exhaust, at start up, and that dissipates as the engine warms up to normal temp. So my question is: is the over-heat the cause of the 1401 code, or the oil & water in the exhaust, from the bad head gasket, the real cause.? And will the code go away, if the gasket is repaired.?

Answer 1

P1401 EGR system

No this would not cause the head gasket, Whether you have a cast iron head  cylinder head or aluminum, the EGR system has nothing to do with the head gasket failure, You need a EGR system , what it does is cool the combustion chamber and control emission. Regardless if the EGR was working or not it was not the cause of a head gasket. When the engine blows out water from start up when its cold it is due to the metal not expanded , when it reaches operating temperature the metal expands, this kinda seals the leaks. When it comes to P1401 this is a typical failure it would of set regardless , Just in the environment that it works in contributes to its failure.

​ Here a typical DPFE it detects exhaust back pressure, just having moisture exiting the exhaust system you can expect moisture or water build up in the DPFE, which would accelerate its failure