'12 Passat TDI codes P240f and P2478

I have a 2012 TDI on road trip the Glow plug first code, I pulled over and did a scan and received the P240f. I cleared the code and proceeded home. A little bit down the road the engine light came on, which resulted in code P2478. I have pictures but I am not allowed to post attachments at this time. I have done some physical troubleshooting. I decided to change the oil while this was ongoing. When I took the skid plate off, I noticed there was engine oil residue on the underside of the transmission. I then started looking around. As I was looking between the engine and firewall from underneath I noticed oil droplets on a couple rubber hoses. I couldn't tell where it was coming from. So I went up in the engine bay from the top and started looking around. I found a Sensor connected to the intake near the firewall directly above the oil on the hoses. The intake manifold had oil residue all over the hose. The sensor has a Purple and yellow and red stripe wire. When scanned with ODB II I noticed the EGR, BPS, EGS, DPF, HCC, AND NOx were flashing red. CAn I get any recommendations?

have you ever used "Sea Foam Motor Treatment additive" ($8 at walmart) I used 25% of it every fill up after oil change 10k and never had problems with my injectors : my 2012 jetta TDI had 326k miles on it when it got totaled car was a work horse !

Seafoam

No I have not. I use it in all my gasoline vehicles. I thought it would void the warranty.
Our forums have suggested, changing oil, fuel filter and clean up the seniors.
Thanks for the help. I appreciate it.

Yeah, adding seafoam to the motor oil is an absolutely terrible idea. Just terrible. There isn't anything much more abusive thing that could be done to the engine than to destroy the oils viscosity and ability to lubricate with seafoam. If the car is still under warranty (I would think so) take it in to dealer for diagnosis and repair.

Seaform additive

I don't think kwiatekch meant to add it to the oil, at least I didn't read that from what he wrote. I did read that he did add it after oil changes, and put it in the fuel tank. I am looking into a dealer. They are about 35-45 miles away. I did read on other forums to change filters and clean the sensors. Some have lead to believe it to be bad Fuel & before this happened my wife got fuel from a place never visited before. It was about 1/2 a tank down when the glow plug and engine Warning light came on.

Thank you all for your input.

Ok, I see that he meant it as a fuel additive now. Still not a great idea, but nowhere near as bad as an oil additive. Seafoam has a good bit of isopropyl alcohol in it which won't be doing the hpfp any favors. And if the dealer had to test the fuel for warranty purposes it would show contamination and warranty coverage of the fuel system would be denied.

I always add any injector cleaner (in my gas engines) BEFORE the oil change, not after. I'm not comfortable having my engine injest even moderately increased doses of injector cleaner, then leaving the oil in the sump for another 10k miles. YMMV!

Now that makes sense. I used to have a diesel escort years ago. It developed a leak, it cost me $900 to have it rebuilt.
If it's a sensor that is malfunctioning I don't believe that it's covered under warranty of the exhaust system itself. That's why I am trying to figure out which sensor is bank 1 Sensor 1 because that is what the error code P2478 leads to. The sensor at the dealership is $300+ plus labor will be probably in the neighborhood of $300-400. When I can get the sensor from multiple suppliers from $75-$150. I noticed that there are 3 sensors between the turbo and the dpf. Which I mentioned in my original post.
Recently, watching a YouTube video, I saw that there are 2 sensors between the dpf and the catalytic converter. Could one of those sensors be the associated sensor?
Another concern I have is the last time I took the Passat TDI to the dealership; they had it for 60+ days. So if I could just get the location of the Sensor I then could test it with a multimeter and a heat gun.

It's probably just a bad egt sensor, but that absolutely should be covered under the emissions warranty.

edit: I looked at the warranty and all sensors are covered. The diagnosis is covered too. I'd just take it in and let them fix it. They are supposed to supply a free loaner vehicle if needed.