L405 Exhaust Gas Sensor

I get this every time I start the car, or as in the case this morning don't start it. My independent has become obsessed with it being the reason for "Restricted Performance" after about a hour of driving. The "Restricted Performance" message only comes on after at least an hour of driving and interestingly never came on before they serviced it. They have also suggested that unless I do something about it the DPF will clog up (I always clear the "Restricted Performance" ASAP either by stopping or using the IDTool) and of course normal performance is restored. They have replaced one sensor (no change) and are now suggesting replacing all 6 which will cost me thousands of £££s but my guess is that it may fix the sensor problem but not the underlying fault, which I have had suggested to me my be an air leak which doesn't throw up a code. Also logic tells me if a faulty sensor is the actual underlying problem the car would go into "Restricted Performance" immediately and not clear so easily. The car runs perfectly with good performance and good mpg. Anyone got any thoughts?

Aldus said:

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I get this every time I start the car, or as in the case this morning don't start it. My independent has become obsessed with it being the reason for "Restricted Performance" after about a hour of driving. The "Restricted Performance" message only comes on after at least an hour of driving and interestingly never came on before they serviced it. They have also suggested that unless I do something about it the DPF will clog up (I always clear the "Restricted Performance" ASAP either by stopping or using the IDTool) and of course normal performance is restored. They have replaced one sensor (no change) and are now suggesting replacing all 6 which will cost me thousands of £££s but my guess is that it may fix the sensor problem but not the underlying fault, which I have had suggested to me my be an air leak which doesn't throw up a code. Also logic tells me if a faulty sensor is the actual underlying problem the car would go into "Restricted Performance" immediately and not clear so easily. The car runs perfectly with good performance and good mpg. Anyone got any thoughts?View attachment 257454

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Is the sensor they changed the recirculation temperature sensor A?

Thats a good question. According to the invoice they replaced SENSOR - EXHAUST GAS - TEMPERATUR part No WDN500130LR and they call it the pre catalytic convertor temperature sensor. As I say one or more sensors my be faulty but how will that help with the underlying problem?

The previous one was from another forum member trying to help.

I do not know your engine but I would guess from what you say that they have replaced an exhaust gas temperature sensor as you say when they should have replaced the EGR temperature sensor.
Someone will be along who knows the car eventually.

Googling "l405 egr temperature sensor A" brings up some good results on another forum across the pond

Aldus said:

They have replaced one sensor (no change) and are now suggesting replacing all 6 which will cost me thousands of £££s but my guess is that it may fix the sensor problem but not the underlying fault, which I have had suggested to me my be an air leak which doesn't throw up a code.

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How much have they quoted?
The EGT senors are under £100 each, so if the garage are charging thousands of £, they're having you on.

As for the fault, unfortunately you're only option is to go by the codes, or good old fashioned investigations.

Funny enough I saw this the other day , alas don’t know how helpful this also is to u @Aldus

https://www.fullfatrr.com/forum/topic48131.html