Melted DPFE sensor. Could it have been related to Seafoam treatment?

[AP9]

I was on the road this weekend and noticed a sort of buzzing sound that was proportional to RPM. Stopped several miles down the road, opened my hood, and found this:

Wasn't getting a CEL but my Scangauge II did find P0401 pending. The vehicle still drove just fine, but it sounded like a tractor with those EGR hoses exposed. As a precaution in case it started knocking, I topped off with premium fuel.

Anyways, to make a long story short, thanks to some old threads on this wonderful forum I replaced my DPF EGR sensor and hoses. It appeared that one of the hoses (which had burst) was clogged with stuff---not sure if it was carbon deposits, dirt, or deteriorating hose material.

I didn't see this coming. The only two contributing factors I could think of are that my oil level is borderline high (but I would think I'd be seeing other issues before anything EGR-related) and that I did run Seafoam through the PCV vacuum line about 2.5 months ago. Could the Seafoam have knocked enough deposits out of the engine to eventually cause such an issue? And could the EGR valve itself still have problems?

 

[AP9]

The vacuum line that goes to the top of the EGR valve was also a bit oily at the manifold side.

 

[2000StreetRod]

flammable liquid

Sea Foam Motor Treatment is a flammable liquid. When you add it to your engine you're enriching the air/fuel mixture. Running excessively rich creates high temperatures in the catalytic converter. Maybe that created back pressure in the exhaust system causing your DPFE sensor hoses to blow off the ports or maybe they just came loose. Then there was exhaust gas flowing out of the hoses melting anything it could reach. I don't allow unmetered fuel to enter my engine except when spraying starting fluid into the intake manifold to see if I have ignition.

 

[AP9]

I suppose that's possible, but I would think something like that would happen almost right away. There was about a 2.5 month / 2000 mile delay here, so I was thinking more along the lines of carbon buildup from the engine that gradually clogged something up in the exhaust.

 

[2000StreetRod]

carbon build up?

You're probably right. I've read that members who run Sea Foam thru their engine often have to replace the spark plugs after due to the crud that is released into the combustion chamber. If it collects on the spark plugs it probably also collects on the honeycomb in the catalytic converter. That might be the start of a gradual build up that eventually increases back pressure. Did you replace the hoses with high temperature rated ones?

 

[AP9]

Yep, got EGR-specific hoses from the nearest AutoZone (the only reason I went there was because I was on the road at the time). Just checked them, they seem fine, though there is a small amount of soft mushy buildup at the edges of fittings for some of the other vacuum hoses I just checked now.