Lately I've been having a problem where my truck will, at idle, surge to ~1200 RPM and run very roughly but without throwing a code (P0606 did show up one of the last few times I drove it, right after I replaced the fuel filters, but it was gone after I messed with the EBP sensor today; this problem almost disappeared after the filter change, but came back strong next time) A couple times on my last drive it also blew dark smoke during the worst of it. This would stop as quickly as it started, and the truck would run fine, until it started doing it much more to the point where it would run high and rough upon startup. One more thing that showed up on my last drive was that when this stuff was happening, my EOT reading would jump all over the place, then immediately return to normal when the truck started running fine again.

My research has pointed me mainly toward ICP, EBP, and VGT systems; this morning when I started the truck it went to ~1200 and ran rough; I cut it off and started again, with the same result. Then I popped the hood and unplugged my EBP sensor, and the truck started and ran fine while I moved it to my driveway to work on it, so I figured EBP was the problem.

I pulled the sensor and cleaned out the tube with brake clean and weedeater string. I also checked the pigtail for fraying (didn't see any); I did see a little bit of green copper corrosion on one of the pigtail contacts, so I cleaned it with a toothbrush and some electrical contact cleaner. The bottom of the sensor looked mostly clogged with soot so I cleaned it as well, and also cleaned the sensor's contacts even though they looked fine. When I started I had assumed I'd probably need to replace the sensor, but since I'd cleaned everything up (and wasn't going to make it to the closest dealer/s parts counter before closing) I decided to try what I'd cleaned. I put the sensor back on and got it good and hand tight and plugged it back in and started the truck just long enough to see it start fine (since I was just testing I didn't put the air cleaner and such back on).

Since it started fine I assumed I was good to go; pulled the pigtail back off and put a little dielectric grease on the yellow (weatherstripping?) and since it was close by I checked the ICP pigtail as well (all good) and gave it some dielectric grease as well. Then I put everything back together, cleaned up, and went for a drive.

I was gone over an hour and the truck ran wonderfully - no problems at all, except that P0472 (exhaust pressure sensor low input), which I'd never seen before, showed up. The most obvious cause seems to be that I didn't plug the sensor back in right (if I'm correct to assume that would cause this code), but I remember plugging it in until it clicked after putting the grease on it, because it took me several tries for some reason (It didn't when I plugged it in to test-start the truck)

Assuming that I do have it plugged in correctly, what is this code telling me? Is my sensor bad after all?

I appreciate any guidance you guys can give me on this.

EDIT: Not sure if this is relevant, but I forgot to mention that I also replaced my air filter today.

Thanks! I took some pics of my pigtail connector before cleaning it, but none came out well. When looking at it such that two openings are on top and one is on the bottom, the top, left opening is the one that was corroded. After cleaning, it was much better than it was before, but not quite as clean as the other openings.

Yes, just fingers only. I got it nice and tight by finger standards, but not as tight as a wrench would have, so that’s definitely possible (which, in hindsight, should have occurred to me before). I’ll get it wrench tight and see what happens.

Thanks!

Awesome, thank you! I will definitely check that before spending (especially since the dealer I spoke to earlier wants ~$100 just for the EBP pigtail). Also, thanks for the wiring diagram, that’s going to be handy in the future, as well!

Thanks again for that wiring diagram, it came in handy! Turns out the ref wire was the one with the corroded connector. I tested it with the engine both off and running but didn’t get any voltage, so I guess that’s the problem. I’ll shop around for a new pigtail and replace it.