Evnin all as some of you may know I have thought I have had poor performance from day one. recently the turbo seems to Hiss/whistle on boost more as though there is a boost leak but I cant seem to see any obvious leaks. the Annoying thing is it doesn't do it while stationary as I got the missus to rev while I looked around. I can only here the Hiss when moving from 2000 rpm upward fairly loudly, so unless I hang off the bonnet while someone drives around I'm at a loss as to where it is coming from or what is causing it. Originally I only had the 17705 code (pressure drop between turbo and DV) but cleared this with a slight improvement in pick up.

I hooked it up to VAG COM again today to see whats what and here is the results:

16514 P0130 oxygen Lambda sensor Malfunction in circuit This is a new one since I done a scan around a month ago, New Lambda Sensor needed?

16795 P0411 Secondary Air Injection system, incorrect flow detected, is this a faulty N112 valve?

17545 P1137 Fuel trim Bank 1 System Too Rich ??????

17705 P1297 Pressure drop between turbo and D.V. Is that the Diverter Valve? if so what and where is this?

18010 P1602 Power Supply to terminal, Intermitent I have had the battery out a few times recently and also connected the negative for DRL's to the negative terminal which may explain this?

Also I came across another part of VAG COM named Readiness???? It claims a status of 0110 1001 and had the folllowing to say:

EGR; Passed Secondary Air Injection; Failed or incomplete

02 sensor Heating; Failed or incomplete Evaporative Emmissions; Passed

O2 sensor; Failed or incomplete Catalyst Heating; Passed

Air Conditioning; Passed Catalyst Converter; Failed or Incomplete

Can Anyone make head or tail of all that. :S

Would a boost leak cause all that or am I looking at a new Lambda sensor also at least

Also not sure where to look for all these valves diverter Valve, boost pressure valve, N249 valve, N112 valve??? I'm not shy when it comes to engines but Have been too used to my last few cars being all diesels and this engine seems to have too many vac pipes for my likeing

Any Help Greatly received.

Edited 18 February, 201214 yr by Bigphil33

17545 P1137 Fuel trim Bank 1 System Too Rich ??????

has your car been remapped? as this is the code that can be thrown up after.

I would doubt it as I don't seem to have enough power or boost to overtake confidently. Unless I have a map but just can't feel it due to other problems.

I had the Lambda & too rich error codes when my breather under the manifold was split

Check the breather system !!

cheers guys, much appreciated. Is this the pipes under the perforated plastic panel at the front or do I have to remove the metal plate as well to see the pipe? Any pics of the pipe(s)we are talkin about? as said, there is one too many vac pipes under there for my liking. Its like a freekin inside-out submarine in there

LOL @ inside-out submarine

You'll only be able to diagnose which pipes are losing boost when the engine is under load so really only on a rolling road. I would hazard a guess that your secondary air combi valve (the big metal valve stuck in the side of the exhaust manifold) might be stuck open (or as you suggested the N112 is at fault and keeping the combi valve open) that would explain your SAI related codes and also the louder turbo noise. Might have also had a knock-on effect on your lambda sensor if there is constantly fresh air coming into the exhaust.

18010 code just means you've disconnected the battery recently. Clear it and it shouldn't come back.

The Readiness test displays the current status of the exhaust/emission componants,when you disconnect the cars battery you will find that it can throw up failed componants,the vehicle has to driven for period of time so that the ECU Can gather data and re-access the componants this should fix the failed readings,unless there is a genuine failed componant.

Edited 20 February, 201214 yr by macatac

Cheers guys . Legends the lot of ya

hmmmm, just searched around for relevant info on the various valves and came across this on youtube about noisy SAI pump on a VRS posibly someone on here.

Just realised mines sounds just like this too. was none the wiser as it was like this when I bought it and this is my first car with this system fitted. So I take it I'm looking at (as chicken_eyebrow said) at a new N112 or a combi valve? or can either of these be serviced at all? Cheap to replace?

are these the two things I need to look at and which is which?

http://i123.photobucket.com/albums/o315/absolutegtr/PIC-0070-1.jpg

Cheers to the member on the audi forum I ''borrowed''this from.

If the SAI is noisy then that's usually because the pump itself is coming apart - get under the car and have a look at it, it's at the front drivers end of the engine right at the bottom of the engine. It's in two halves that are held together by rivets and the rivets often wear out, if you can see a gap between the two halves thats where the noise is coming from.

That doesn't necessarily mean the combi valve is shot but it's worth fixing the pump anyway and see if that gets rid of some of the codes.

The fix is either to get the pump off and replace rivets with bolts or bin the whole SAI system entirely.

Again here is another ''borrowed'' picture that I think answers some of my questions and may help others like me too.

Am I correct in thinking on this Audi the valves are underneath the manifold but on ours they sit on top?

are these the two things I need to look at and which is which?

http://i123.photobucket.com/albums/o315/absolutegtr/PIC-0070-1.jpg

Cheers to the member on the audi forum I ''borrowed''this from.

They are both N112 valves not sure what car that pics from but on the VRS there is just the one and it's on underside of the metal plate in front of the dipstick along with the N249 valve.

I would try checking and fixing the rivets on the pump first (23 on that diagram), clear the codes and do a few cold starts then see if that gets rid of the secondary air fault code. If it doesn't then look at the N112 (12 on the diagram) or combi valve (6) or even just get a blanking plate and get rid of the whole SAI system.

Cheers Again Chicken, it's all startin to make some sort of sense now.

Just found this as well - might come in handy when checking the components. It's based on the same engine but from the Audi TT:

http://www.vaglinks.com/Docs/Audi/TT/Audi_TT_Sec_Air.pdf