Exhaust Back Pressure Sensor P0471

[jack9920]

Hi,

just had the check engine light come on with the code P0471 on diagnostics; this is the Exhaust Back Pressure sensor

Ive had the sensor replaced for a brand new one, and the light’s still on, anybody else experienced this?

don’t really know what to do from here as Mercedes want another £100 to check again!

 

[OneForTheRoad]

Did you use a genuine part replacement ?

 

[grober]

Exhaust manifold pressure sensor - P0471

 

[jack9920]

Did you use a genuine part replacement ?

Yeah I used a part straight off the shelf at mercedes, turns out it was a blockage in the EGR pipe that filters combusted air back into the engine to keep emissions down, going to start using RedEx and other products to keep the carbon build up at bay in the future.

It’s now cost me nearly double to have the real problem sorted, so for anyone reading this with the same issue in the future: Don’t think you know what the problem is! take it to mercedes and just get it sorted first time!

 

[Cookstar]

Hi,

just had the check engine light come on with the code P0471 on diagnostics; this is the Exhaust Back Pressure sensor

Ive had the sensor replaced for a brand new one, and the light’s still on, anybody else experienced this?

don’t really know what to do from here as Mercedes want another £100 to check again!

Oh yes just going down same route. Did a resistance test and fine but also keep getting intermittent code from emissions sensor? Both are on same loom so now thinking relay perhaps? Can happen on coolant sensor and swapping relays around can pickup up if its a relay problem. Just need to work out what relay governs these two sensors?

 

[02pschofield]

Oh yes just going down same route. Did a resistance test and fine but also keep getting intermittent code from emissions sensor? Both are on same loom so now thinking relay perhaps? Can happen on coolant sensor and swapping relays around can pickup up if its a relay problem. Just need to work out what relay governs these two sensors?

Hi Guys im having the same issue now with mine wondering if anyone would be able to help me with what i should do.

 

[Cookstar]

Hi Guys im having the same issue now with mine wondering if anyone would be able to help me with what i should do.

Guys they are all false positives if back pressure pipe is blocked. If BP sensor is kicking back code then replace pipes then should clear up other faults.

 

[OneForTheRoad]

Hi Guys im having the same issue now with mine wondering if anyone would be able to help me with what i should do.

Don't confuse exhaust back pressure sensor with dpf sensor . Some false advice given on this thread I notice.