I wanted to share some info, I hope it isnt already posted somewhere on the forums and I am attempting to reinvent the wheel.
I plugged in the autoenginuity and was getting a p0470, Exhaust Back Pressure Sensor Circuit Malfunction. I also noted that the sensor was reading about 20 psi. I followed the website by guzzle (Welcome to guzzle's Exhaust Backpressure Sensor Cleaning Maintenance Web Page
) for cleaning out the tube and sensor. The tube was pretty much completely packed with soot, and so was the sensor. I cleaned out the sensor enough to see into it a 1/4 of an inch. I put it all back together, and started the truck up. I still had the code, and the pressure was still stuck at around 20 psi.
I then figured that the exhaust back pressure sensor was screwed, so I figured that anything I do to it now wont matter because I need a new one. I took an o-ring pick, and slowly started digging my way into the sensor and more and more soot kept coming out. I reinstalled the sensor and started up the truck. The p0470 was gone, and It was registering a small change in back pressure, but the value did not change much. I took the sensor off again, dug some more soot out, and hit it with the air compressor and kept going till I could not see any more soot coming out. I did notice a few little chunks of blue rubber come out, so I am pretty sure I scarred the rubber diaphragm on the inside of it. I was banking on getting a new sensor so I wasnt worried. I reinstalled it, fired the truck up and my code was still gone, and my exhaust back pressure was down to 14psi, and moved according to engine rpm instead of just being stuck at 20psi.
I have attached a picture to describe what the inside of the sensor looks like, in order to show where all the soot can hide. I think when I scarred the diaphragm, it was closer to the far edge of the blue area, so be careful when carving away at soot.
Hope this helps.