Help to locate exhaust Temp Sensor

[Leighspain1975]

Hi Guys

Just some quick advice please if you can. I have a 2012 3.0tdi engine CDUC engine code and have a faulty exhaust temp sensor #2. Any ideas where it can be cause I can’t find it anywhere.

Sensor #1 is at the Turbo
Sensor #2 ?????
Sensor # 3 is before the DPF
Sensor # 4 is after DPF

Checked everywhere.
Any help would be great

Cheers

 

[Tendaimwari]

What code are you getting?

 

[Leighspain1975]

Think I worked it out.
Sensor # 2 is actually the Lambda O2 sensor at is at 0 because it doesn’t read exhaust gas temp but apparently they do in other models.

No codes - Just trying to solve an intermittent probably that has been bugging me for months Audi won’t do anything.

Basically car runs super smooth and then suddenly rough and it keeps on doing this. Tried absolutely everything and wondered if it was the O2 sensor but no. Seriously given up where to look.

 

[fingermouse]

does it run rough in normal but ok if put into sport ???

 

[Leighspain1975]

It runs rough in all modes.
It’s strange I can start the car and it runs as smooth as silk. No harsh diesel clatter and very responsive. I could switch off the engine for 5 minutes and start again and it’s back to a bag of nails. Still runs ok but no where near as smooth or refined as when it’s running great.
I done a side by side on vcds to try and spot any hints of sensor failure but nothing all readings are exactly the same. Car has new injectors so can’t be fuel related either. I have noticed though the car runs very smooth during a Dpf regeneration. Not before, not after but during which has got me scratching my head.

 

[Leighspain1975]

Hi guys

Happened again today. Car is driving normal I guess but really rough on low rpm and in traffic and doesn’t seem to have the shove it should have. It almost feels like it’s pulling something like a 100 ton stone. Even decelerating it slows down really quick without braking like their is a resistance.
Anyway car suddenly changed again today diesel clatter disappeared completely engine sounded fantastic and was incredible acceleration.

I stopped and switched of the car. Low and behold the fans are running so I quickly plugged in VCDS and the car has been regenerating the Dpf again. After it stopped the car sounded like a bag of nails again and went back to it’s horrible self.

It seems to only run perfectly when it’s doing a Dpf regeneration.
Any ideas why this would be ?.

Cheers