Author Topic: P0472 and p0471 fault codes  (Read 2741 times)

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Offline Deanktb

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P0472 and p0471 fault codes
« on: September 15, 2018, 07:19:14 am »
Hi,hoping someone can help. I've got a 63 plate 2.2d sel nav estate. Recently had front tyres and brake pads changed. Next day drove car and it came up with scbs inspection,engine inspection and traction control light was on. Car ran fine apart from I couldn't use cruise control  istop didn't work and the display that tells you what gear you are in wasn't working. Put it on a cheap diagnostic scanner and came up with these fault codes p0471 and p0472 which related to exhaust pressure sensor. So I  bought a new pressure sensor  and fitted it and cleared codes.  Now I'm still getting same error codes. But now I'm getting low power under 2000 rpm and when I take my foot of the throtle engines revs are delayed before they start to drop. 

Offline apav

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Re: P0472 and p0471 fault codes
« Reply #1 on: September 15, 2018, 01:10:15 pm »
It sounds like a lot of random problems came together.

If you can find what triggered the problems, then you could do something about it.

Removing the wheels, replacing the pads and the tyres and putting the wheels back, it does not seem like what caused the problem.

But if they hit the car, or messed with something else, then you have to investigate in this direction.

The exhaust pressure sensor could have been faulty but it could also mean that the DPF died. I am not sure if it is healthy to keep replacing parts like that.

Offline Deanktb

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Re: P0472 and p0471 fault codes
« Reply #2 on: September 15, 2018, 04:03:31 pm »
The exhaust pressure sensor was the only fault that came up on the diagnostic. Apparently this causes the other lights (scbs,traction control and engine management lights) to come on. That's y I changed the exhaust pressure sensor. Was just trying to c if I could resolve it before mazda chucked a load of expensive parts at it trying to fix it. The car has only done 37000 miles and does regular motorway runs so dpf should be ok. Also have had no lights come up for dpf or fault codes. Was wondering if it could be something related to exaust pressure. sensor

Offline welshevan

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Re: P0472 and p0471 fault codes
« Reply #3 on: April 27, 2020, 03:24:09 pm »
I have the same fault and it appeared after I had brakes replaced , did you solve yours after??

Offline Sebforce1

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Re: P0472 and p0471 fault codes
« Reply #4 on: June 22, 2020, 07:24:20 pm »
I have the same fault and it appeared after I had brakes replaced , did you solve yours after??

Hello Folks,

I'm having a similar issue on my 2016 Mazda 6 2.2. P0472 error code, DSC malfunction and SCBS malfunction all coming up and the engine is not accelerating normally. I've changed the exhaust pressure sensor but the error lights won't go off.

I haven't had any work done on my brakes recently.

Did you ever get to the bottom of what caused your issues?

Thanks

Offline Sebforce1

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Re: P0472 and p0471 fault codes
« Reply #5 on: July 24, 2020, 03:15:52 pm »
I've managed to solve the issue on my car. My Mazda 6 was not accelerating correctly and it was showing the Engine Warning Light, DSC Light and SCBS Malfunction. My diagnostic reader was giving me the following codes:

P0471- Exhaust Pressure Sensor A Circuit Range/Performance
P0472- Exhaust Pressure Sensor A Circuit Low
P2227- Barometric Pressure Circuit Range/Performance

The P0471 & P2227 only showed up very intermittently whereas the P0472 was constant.

I replaced the dual-hose exhaust pressure sensor to no avail, but it turns out the Mazda 2.2D has two seperate exhaust pressure sensors which I was initially unaware of. The sensor is at the rear of the engine behind the valve cover, near the turbocharger. You need to remove the plastic engine cover and heat shield to get to it.

I contacted Mazda and ordered a new sensor however this model of sensor has been discontinued and replaced with a new design. The old sensor was covered in carbon deposit so i suspect it had just become blocked and could no longer register the pressure (my car has only done 34,000 miles!!). The new sensor comes included with a shorter rubber hose, mounting bracket and extender cable which all need to be installed for the new sensor to fit correctly. It's quite a fiddly job and you'll need a pair of long-nose pliers to get the hose spring clamps off but it's doable. Once installed, I reconnected the battery and cleared the Engine Warning Light and the car is now running and accelerating normally again!! :D

Part Numbers:
Old Sensor- SH02-18-211C
New Sensor- SHY6-18-W00

All in all, the new sensor cost around £69 and about 45 mins to install. My local Arnold Clark Mazda quoted me £128 just to run a diagnostic check so instead I just bought a £20 code reader from Amazon. Hopefully this can help someone save some cash and get their car back on the road.