Exhaust Pressure Sensor Issues

[Wasque89]

Hey guys, I scanned my truck a few weeks ago because the monitors are not ready after a long while of driving. I had a back pressure code so I cleaned the tube and sensor. Put everything back together and still had no reading on my CTS. I ordered a new one and just installed it and still have no reading. The bottom of the old sensor was all wet and covered in soot. Not plugged but covered in oily soot. Any ideas? Nervous I’m dealing with something more major than monitors not getting ready. Also the exhaust brake seems to be working but doesn’t seem to slow the truck as hard as it used to.

 

[Bob4x4]

You may want to add a signature line with vehicle info and what the actual dtc is to get better response

 

[Wasque89]

Sorry I posted that off my phone quickly this morning. I first had the code P0471 so I cleaned the exhaust sensor the port next to the Thermostat as well as the line from the manifold. I have not seen the code again in about 300 miles but my Edge CTS is reading 0.0 for exhaust pressure. I just replaced the sensor with one from Genos and cleaned the housing a manifold tube again and it still seems to be reading 0.0 even with the exhaust brake on. when i swapped out the sensor I did notice that it was covered in oily soot again after about 300 miles of driving. This whole issue started when i Failed MA state inspection because of exhaust sensor not being ready. I have driven quite a bit and still have no exhaust sensors ready. The truck is also getting about 8-9 Miles per gallon. any insight would be greatly appreciated I'm just not sure where to start.
Thanks!

 

[zetatre]

A silly question: when you cleaned the tube, did you remove it from the exhaust manifold? I use carb cleaner and sprayed from one end to make sure it comes out the other. Also clean the orifices on the exhaust manifold and the thermostat housing.

For good measure pull the boost sensor on the intake horn and wash that off as well.

 

[Busa Dave]

Mine has done this almost since new. Only on long trips after many hours of highway driving and right after I have to fuel. Just clear the code every time. Not worth taking it in for that at least for me..