So, Dads A3 threw a CEL a few weeks ago. Finally got around to fixing it.

The code was P0470 (Exhaust pressure sensor)

110$ at the dealer (who had it in stock) for the sensor, and I was on my way to fixxing.

Now, something to note here. VAG 2.0L TDIs actually have 2 of the bloody things. one obvious, one note.

So the first one that I changed was G505. This was the part number 076 906 051B
The second location, G450, uses part number 03G 906 051G

So after I replaced G505, and the CEL still showed up (yes, i have a scan tool and reset it) I did some digging and found the second sensor.

As far as I can tell, the 2 sensors do the EXACT same job. The 051B is actually a updated/upgraded/better version of 051G.

“G505 measures the differential pressure across the DPF. This information used to develop one of two soot load models used to trigger DPF regenerations. G450 is used to help position the Low Pressure EGR Valve. It is not likely that these sensors are interchangeable. They are both differential pressure sensors (ie the compare differences in pressure between two points). This implies they have been engineered for their specific locations (i.e. correct DP range, zero setpoint, electrical properties).

I’m sure you intuitively feel that this may not be the best thing to be doing. Hence your question. Just because the physical sensors look the same, given the different P/N’s there is no reason to believe they can be interchanged. Germans are if nothing else efficient. If the same sensor worked in both locations they would have the same P/N. “

Hmmm.....maybe down the line i’ll replace the sensor G again. We will see if it works for the time being.
EDIT#2: So, reading further, it DOES look like the 2 do similar things...hmm...Will have to check with a dealer about this one.
EDIT#3: checked with dealer. the 015G has been dropped in favour of 015B. So i am good to go.

So, I replaced G405 with the ORIGINAL sensor from G505.

Clear code, start engine up, go for a drive. CEL is gone!

I will say this: G450? what a pain in the ass it was to remove. The clamp is facing the firewal...and you cant really move it. (that silver thing on it is just a heat shield. It has snap buttons on it)

Now, off to get that door ding pulled out :D