Lamda sensor or not????

[bikedoctorr]

Hi all
I wonder if you can help me

I have a 2004 A3 8p 3.2 Quattro sport. I have the mil light on
I’ve scanned it with vcds and it’s saying the lamda sensor 1 Bank 1 is implausibly lean.
and pump current trim circuit open intermittent.
Now I’m pretty sure it just needs a new lamda sensor I just want to be sure, but from what I’ve read on the net it could also be wiring or maf sensor.
The wiring I have plugged s2 into s1 plug. Couldn’t do the so called broken s1 into s2 plug as they don’t fit. this just gave an error that s2 was not working so I guess this proves with s2 in s1 plug there’s no fault with the wires. Plus if it was the maf as it feeds both banks I’m guessing both would lean lean not just one sensor. Is this correct thinking ???

I have looked at the sensor voltages. Bank 2 is variable all the time just over 1 v but senor one is on 1.9v all the time. Bank one adaption is on 25% all the time where as 2 is on 1 to 3%.

if you think it’s the sensor then are there any ones you would go for or avoid. I’ve seen the Bosch ones seen to be a good buy.

 

[bikedoctorr]

I do have vcds screen shots of all the voltages but I can’t upload as it says there too big a file

mid theres any more info need I’m happy to give. Not posted in here before so not sure what else you’d need

 

[bikedoctorr]

Update. Bosch lamda sensor brought from Germany and all is good. All voltages now reading these same for both banks.

 

[rum4mo]

I like NTK Lambda sensors, VW Group's Lambda sensor supplier of choice I think, sometimes these systems are very fussy about which brand of Lambda sensor if fitted long term, ie a quick fault fix, but another need to spend more money some time later - but not much later.

 

[bikedoctorr]

As I got no reply’s I went with a good known manufacturer. I see on another site someone used a cheaper one and it failed quickly. And that Pearson was recommended the Bosch sensors don’t I went with that one.

 

[rum4mo]

I very rarely wander into this section so I missed your initial postings.