2.0 TDi Ultra CNHA EGR and cooler removal and cleaning

**Sambor11** · 26-11-2020,05:18 PM

Originally Posted by liam walsh

Some very tricky limited access water pipe clamps down in that area.

Coolant today went below min again. I top up yesterday and can smell dump when I opened bonnet. And now the best part! Came back home today and plug vcds. And what?

2 Faults Found:
20169 - Exhaust Pressure Sensor 1 (G450)
P0471 00 [096] - Implausible Signal
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:

9764 - Exhaust Pressure Sensor 1 (G450)
P0470 00 [032] - Malfunction
Intermittent - Not Confirmed - Tested Since Memory

This faults didn't appear before but now exist! Like you said before this sensor was faulty, but why didn't show before? I will call Audi tomorrow! They probably didn't check faults after they replaced cooler.

**liam walsh** · 26-11-2020,08:16 PM

Originally Posted by Sambor11

Coolant today went below min again. I top up yesterday and can smell dump when I opened bonnet. And now the best part! Came back home today and plug vcds. And what?

2 Faults Found:
20169 - Exhaust Pressure Sensor 1 (G450)
P0471 00 [096] - Implausible Signal
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:

9764 - Exhaust Pressure Sensor 1 (G450)
P0470 00 [032] - Malfunction
Intermittent - Not Confirmed - Tested Since Memory

This faults didn't appear before but now exist! Like you said before this sensor was faulty, but why didn't show before? I will call Audi tomorrow! They probably didn't check faults after they replaced cooler.

I'm not 100% sure because it's a while since I looked at this stuff but ts possible that the G450 is the differential pressure sensor for the dpf and not the MAP sensor I mentioned earlier in the thread. The diff press sensor is an important one for DPF regens so would need looking at ASAP if it is. Is your oil level increasing do you know or have you checked?

**liam walsh** · 26-11-2020,08:45 PM

Might be time to consider trading the car in for another while you have no lights on the dash. Early A4 B8.5 adblue cars are not the most reliable as they age. Only I can do 90% of the jobs myself I'd have got rid of mine at this stage. Only today it threw up an engine light due to a dodgy glowplug or wiring.

**Sambor11** · 26-11-2020,10:04 PM

Originally Posted by liam walsh

I'm not 100% sure because it's a while since I looked at this stuff but ts possible that the G450 is the differential pressure sensor for the dpf and not the MAP sensor I mentioned earlier in the thread. The diff press sensor is an important one for DPF regens so would need looking at ASAP if it is. Is your oil level increasing do you know or have you checked?

Engine oil is normal

**liam walsh** · 26-11-2020,10:25 PM

Originally Posted by Sambor11

Engine oil is normal

Keep an eye on it . If the car attempts dpf regen too often diesel can get into the oil.

**Sambor11** · 27-11-2020,08:31 AM

Originally Posted by liam walsh

Keep an eye on it . If the car attempts dpf regen too often diesel can get into the oil.

Regen is normal as well. Usually after 300 miles. Call them today and see.

**Gazwould** · 27-11-2020,10:10 AM

Jesus what a pain this emissions equipment is , I'd get Frank to sort it out .

**liam walsh** · 27-11-2020,10:16 AM

Going by past experiences of people that work regularly in dpf deletes / adblu deletes this particular generation of VW group engine do not take wheel to dpf / egr cooler deletes . Within a short space of time after delete the engines end up with bigger issues.
The Adblu you can delete as long as you dont have the adblu system fault countdown to no restart on the dash but will you make it through mot after I dont know.

**Sambor11** · 27-11-2020,10:44 AM

Originally Posted by liam walsh

Going by past experiences of people that work regularly in dpf deletes / adblu deletes this particular generation of VW group engine do not take wheel to dpf / egr cooler deletes . Within a short space of time after delete the engines end up with bigger issues.
The Adblu you can delete as long as you dont have the adblu system fault countdown to no restart on the dash but will you make it through mot after I dont know.

Should I replace this G450 sensor? Is just one or two?

**liam walsh** · 27-11-2020,10:59 AM

Get the dealership to diagnose it . You've had a lot of work done in the area it could be a cracked vacuum hose, bad sensor , loose plug, damaged wire. Tell them you didnt have the problem before they worked on it and now you have . You know this because you did your vcds scans before and after.