[Dazza335iC]

I got an SES light 2 days ago, and pulled the following codes with TorquePro:

P0471 Exhaust Pressure Sensor Range/Performance
P0473 Exhaust Pressure Sensor High

A quick Google search indicates that these codes often show up at the same time, and are usually due to a blockage in the sensor line. I figured it could be clogged/plugged with soot, so yesterday I took off the fitting where it connect to the exhaust manifold (just before the first turbo). I saw no blockage or soot buildup, though I did blow it out with a can of compressed air. Put it back together, drove it ~20 miles, and the errors remained.

This morning I started the car and instantly got Limp Mode. Pulled codes again and now there's a third one:

P0472 Exhaust Pressure Sensor Low

Limp mode stayed on until I gave it some throttle, then it went away. Then it came back as I coasted, then went away again with throttle. On/Off of limp mode every 5-10 seconds... very frustrating.

Anyway all signs lead to a defective pressure sensor, which runs about $150 online or $180 ad the dealer with a CCA discount. Before I spend the $, is there anything else I should be looking at? The car still makes massive power so I don't think the DPF is clogged, and the regens still seem to be going off at regular intervals.

[TorqueAddict]

It could be your SCR that is clogged, even if DPF is fine.

[Dazza335iC]

I would think that a clogged SCR would show simply a "High" exhaust pressure errors, not High, Low, and Range/Performance errors. But I suppose it's a possibility. I already have my SCR deactivated via the JR tune, so gutting it wouldn't be the end of the world.

[Hoooper]

sounds like the 0471 code is checked at key-on, which makes sense, and if so could only really be caused be either a sensor failure/clog or wiring issue.

[Dazza335iC]

Pressure sensor replaced, everything is totally fixed! Thankfully it's super easy to get to.

[335dwanted]

Originally Posted by Dazza335iC

Pressure sensor replaced, everything is totally fixed! Thankfully it's super easy to get to.

Tried this weekend to replace the DPF press sensor but could barely get my fingers on it. I removed the airbox, engine cover and microfilter cowl. I did not unbolt the vacuum block, perhaps that is what I need to do next.

Please advise how you did this "super easy". Thanks.

[Yozh]

Originally Posted by 335dwanted

Tried this weekend to replace the DPF press sensor but could barely get my fingers on it. I removed the airbox, engine cover and microfilter cowl. I did not unbolt the vacuum block, perhaps that is what I need to do next.

Please advise how you did this "super easy". Thanks.

You are talking about the differential pressure sensor and he did the exhaust pressure sensor. There is one of each on our car.

[335dwanted]

Originally Posted by Yozh

You are talking about the differential pressure sensor and he did the exhaust pressure sensor. There is one of each on our car.

My bad, thanks for the clarification Yozh.

[Dazza335iC]

Yes, it's kind of confusing as the sensors have similar names, but they are different parts. THe exhaust pressure sensor was held on with just 4 torx bolts.