Please help. P0471 Exhaust Pressure Sensor

[JusticeNL]

I have already do:
(F858) EXHAUST GAS PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
(K35) EXHAUST GAS PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
(K934) EXHAUST GAS PRESSURE SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE
(F858) EXHAUST GAS PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(K35) EXHAUST GAS PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
(F858) EXHAUST GAS PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE
(K35) EXHAUST GAS PRESSURE SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
(K934) EXHAUST GAS PRESSURE SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE
NEW EXHAUST GAS PRESSURE SENSOR

So I have 2 options now:
INTERMITTENT DTC or ENGINE CONTROL MODULE (ECM)
I will look to the DTC....and dont hope its the ECM...is it possible to check if the ECM is working or not?

[MADDOG]

You need a scan tool to tell if the PCM is operating properly. That tool, unfortunately, won't be found many other places besides a dealer.

[jackwalton]

Originally Posted by vyckal

the name is Exhaust gas pressure sensor
It's under the hood, not so far from turbo - in the right side, connected to the body with two tubes.

P0471 Possible Causes:
INTERMITTENT DTC
(F858) EXHAUST GAS PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
(K35) EXHAUST GAS PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
(K934) EXHAUST GAS PRESSURE SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE
(F858) EXHAUST GAS PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(K35) EXHAUST GAS PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
(F858) EXHAUST GAS PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE
(K35) EXHAUST GAS PRESSURE SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
(K934) EXHAUST GAS PRESSURE SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE
EXHAUST GAS PRESSURE SENSOR
ENGINE CONTROL MODULE (ECM)

The sensor with 2 pipes on is NOT the Exhaust back pressure sensor. The 2 pipe sensor is used to decide when to regen the DPF and has nothing to do with P0471 code.

P0471 code is generated when the difference between the Exhaust Pressure Sensor signal and the Atmospheric Press Signal is greater than 5.8psi for at least 3 seconds.
P0471 code is derived from 2 seperate sensors. It is NOT taken from the sensor with 2 pipes on.
The photos of the 2 sensors in different posts above are NOT the Exhaust Pressure Sensors. From the above posts I'm not sure that the correct sensor has been changed.


You said in a previous post: Also the exhaust can't pull out the pressure. If i give gas and someone else put his hand to the exhaust you feel almost nothing. We thought also that it could be the EGR. We have checked the EGR yesterday but it seems OK.

It appears you may have a blockage in the exhaust system somewhere and the P0471 code is coming up because it is telling you about this.

Jack

[paul@thecustom300cshop]

Could the DPF be clogged?

[Simon@thecustom300cshop]

It does sound like the dpf could be blocked.

[chrisp]

Originally Posted by paul@thecustom300cshop

Could the DPF be clogged?

Thats what i was going to say Paul. Disconnect the flange at the front of the DPF then fire it up and give it a try i think we suggested doing this to someone elses a bit back and it then revved clean (i presume when you say "stutters" you mean it won't rev) if it's ok then your DPF is clogged

[badgx]

This is ghetto, if anyone is brave enough to try this if its small enough to fit in a large tub or bucket full of warm dishwasher liquid & after left over night, give it a pressure wash. Who knows it may work?

Cleaning dpf filter - YouTube

Cleaning dpf filter - YouTube

[JusticeNL]

Hi Guys,

If the DPF is clogged should I get no other fault code? I think the problem is with clearing the DTC.
What we do is clear the DTC with a normal scan tool. No I have found something witch this fault code (P0471) and it says that I have to clear dthe DTC in the Engine Control Module (ECM). Is this a difference clear method? I hope that this will be the problem.

[jackwalton]

Originally Posted by JusticeNL

Hi Guys,

If the DPF is clogged should I get no other fault code? I think the problem is with clearing the DTC.
What we do is clear the DTC with a normal scan tool. No I have found something witch this fault code (P0471) and it says that I have to clear dthe DTC in the Engine Control Module (ECM). Is this a difference clear method? I hope that this will be the problem.

No you dont need to concentrate on clearing the code you need to fix the fault. I suspect the code is identifying a genuine fault. The codes are supposed to be a guide to identfying the problem. Dont just asume you have to clear the code from the ECM to get the car running normally.

The clue to your problem is that you have very little gas flow through the exhaust. Fix the prbably blocked exhaust system and the P0471 code will prbably disappear. Follow the suggestion in the above post and disconnect at the DPF and run the engine.
Probably a blocked system as suggested previously.

Jack