P0471 exhaust pressure code.

[RDThompson]

P0471 is popping up twice now in about three weeks.
I recently had the EGR cooler flushed and EGR valve cleaned.
The truck is performing normally with plenty of power. The code is easily cleared with my Edge monitor.

Has anyone encountered this issue yet.

My truck is an 08 with the 68RFE and 4wd.

Any enlightenment would be appreciated.

 

[sag2]

Remove the pressure sensor from the water outlet and start the engine. Make sure you have good exhaust flow out of the mount. The line is small from the manifold to the water outlet and easily plugged with soot.

 

[Bob4x4]

Or you can pull the sensor to check flow..The orifice can be cleaned with a stiff wire

 

[RDThompson]

Or you can pull the sensor to check flow..The orifice can be cleaned with a stiff wire

Hi Bob, Thanks for the reply, do you happen to know the size of the orifice in the water outlet that passes through to the tube? Mine is plugged and I'd like to try clearing it out with a bit in a pen vice. Once I get all the way through I can probably finish up with a tip cleaner from my torch.

 

[RDThompson]

Remove the pressure sensor from the water outlet and start the engine. Make sure you have good exhaust flow out of the mount. The line is small from the manifold to the water outlet and easily plugged with soot.

Thanks for the reply. I'm still trying to clear the orifice without making things worse.

 

[Bob4x4]

You can pull the sensor and fill the hole with egr cleaner let soak a bit then go in with a stiff wire and start to work it. Since it is a tight angle a tip cleaner won’t work unless you pull the tube. I normally use a piece of flux core wire