Power problem

[Julian smith]

Hi guys bought my 05 A3 2.0tfsi
Quattro which almost instantly developed power loss,
So changed n75, pcv, and pre cat 02 sensor not much but some brief improvement, then had remap which helped a lot at higher rpm but not that special low down power,
Then epc light comes on codes are as follows
P0321 engine speed sensor g28
P0100 maf sensor
P3266 b1 02 sensor
P0441 eval emission control system
P1388 throttle monitor obw
Car is now jerky also
A pal who works for the as said it could be one fault throwing up all codes.
I'm a bit overwhelmed and don't know what to replace first.
Please help and thanks for your time

 

[samuelh_888]

Clear all the faults, take it for a drive to see what comes back and start from there.

You may have been better to sort the issues before the remap - maybe the map is masking something?

Give your MAF and throttle body a clean and change the DV valve. I think the DV is off the turbo on your model (pain to get to). Possibly change the crank position sensor too, this could be causing a couple of the issues.

 

[Julian smith]

Thanks pal DV has also been changed but will try to get codes cleared

 

[abmat]

P0441- i cleared this by unplugging then plugging back in the n80 valve.

To eliminate this you can remove it and tap it on a surface. If carbon drops out you need a new one.

http://wiki.ross-tech.com/wiki/index.php/16825/P0441/001089

 

[abmat]

I would start with the MAF first

 

[ScottyP45]

Hi mate, I had similar issues with a 1.9 tdi a couple of years ago, loads of sensors went down, no boost, loads of codes in the ecu that would not clear....it was a fuse buried in the ecu main plastic enclosure, under the actual ecu so couldn't be seen without pulling the metal ecu out of the box. It supplied power to all of the engine sensors. MAF, MAP, boost valve, cant remember the whole set but there were a good few on the circuit.

If you have lots of engine sensors or actuators down and the codes won't clear, check they actually have a 12v supply or your wasting time and money replacing them.

 

[Julian smith]

P0441- i cleared this by unplugging then plugging back in the n80 valve.

To eliminate this you can remove it and tap it on a surface. If carbon drops out you need a new one.

http://wiki.ross-tech.com/wiki/index.php/16825/P0441/001089

Thanks bud was going to do n80 next

 

[Julian smith]

I would start with the MAF first

Cheers mate I've heard remapping can cause maf issues, so given car to a decent Audi mechanic who knows these engines inside out

 

[Julian smith]

Hi mate, I had similar issues with a 1.9 tdi a couple of years ago, loads of sensors went down, no boost, loads of codes in the ecu that would not clear....it was a fuse buried in the ecu main plastic enclosure, under the actual ecu so couldn't be seen without pulling the metal ecu out of the box. It supplied power to all of the engine sensors. MAF, MAP, boost valve, cant remember the whole set but there were a good few on the circuit.

If you have lots of engine sensors or actuators down and the codes won't clear, check they actually have a 12v supply or your wasting time and money replacing them.

Cheers buddy have bitten the bullet and handed over to a experienced mechanic who tunes these engines hopefully he can get to bottom of issue