HDI exhaust temp sensor

[dnsey]

My downstream exhaust temperature sensor has become intermittent, and will have to be replaced.
I think I've established that all the HDI engines use the same sensor (if fitted), apart from the lead lengths.
I suspect that it might be a standard K-type thermocouple, which will be much cheaper than the official part.
Does anyone know if that's the case?

[Paul-R]

What car and year is this?

I was under the impression that HDi engines (certainly the early and middle ones) were simple two-way (or is it single?) cats which are unmonitored. It's surely only the latest SCR cats which have sensors to monitor the temperature for the AdBlue additive? Then there is the DPF which is certainly monitored.

[dnsey]

It's the 136HP 2.0 HDI in a facelift C5.
Lexia refers to it as the post-cat temp sensor, but you're right, it's actually monitoring the DPF.

[Paul-R]

I wish you well in your quest but can't offer anything positive.

I wondered a similar thing about the outside temperature sensor in the door mirror but found a S/H one at the scrappy for not much money so never proceeded any further.

[dnsey]

It turned out to be a frayed cable in the end, where it had been chaffing against something. A Few minutes with the soldering iron and a bit of heat-resistant sleeving sorted it.
FWIW, there seem to be only a couple of sensors across the range, but the part numbers vary with cable length.

[Paul-R]

Good news and well done. Another few pennies saved for better things.