Getting Fault Codes 00537 & 00561 - Help please

[minim]

For checking for leaks the best tool is like prj suggested something to set pressure on to the system. When I tested mine recently I went and bought different plumbing parts, some connectors and a pressure regulator and made the tool in the picture below. I hooked it up where the MAF sensor was and set a low pressure that was not even visible on my gauges to not damage the turbo. I was then able to find a leak using some soap water put on the hoses so I could see where it was. I guess this is a primitive way of doing the test but it's for sure better than a visual inspection as you won't be able to see all leaks. Be sure to disconnect and block the breather hose and leave the oil cap off while putting pressure to it even if it's low pressure. Do research before doing this tho so you don't break anything on your car (or yourself)

[veneto rs2]

No Dave I was referring to the #29 in this picture.

The other one that you posted could cause problems but mainly under boost not on idle because the throttle door which is after that part, it's closed on idle.

[UrS4boy]

Maybe MAF poor contact

This is one of the first things I suggest in my Missing and Hesitation diagnostic post that I linked above:

http://forums.quattroworld.com/s4s6/msgs/22611.phtml

[Guslotti]

I have noticed a slight misfire when accelerating at low revs, seems do it once as if it misses a spark or something. I cleaned my plugs and my G70 but it still does it. I thought it may have been the stupidly hot weather we had a few weeks back but it's still doing it now when the temp has now cooled.
So, I thought I would put the 'tool' on it..... Did this about a week ago and got 00537 and 00561. I reset them but again today checked them and they are back again.

I have looked on the Ross-tech site and know what the both mean - but - could the two be related in any way? Could, say, the Lambda sensor be shot? It's only a cheap one I fitted 40K ago?

00537 = Oxygen Sensor Control
00561 = Mixture Adjustment Control.

Any help appreciated.
Thanks

Maybe MAF poor contact

[UrS4boy]

I had those codes for ages and bad idle specially with ac on and on hot climate eventually the engine would stall on carrering to a traffic ligt or to a easy stop. Found that the rubber elbow that connects the ISV idle valve to the intake manifold had a small crack. Stefano

I believe Stefano is referring to this hose:



which typically rips somewhere like this:



More ABY/ADU boost leak possibilities:

http://www.s2forum.com/forum/showthread.php?t=63974&highlight=ADU+boost+leak

[veneto rs2]

I agree with prj

I had those codes for ages and bad idle specially with ac on and on hot climate eventually the engine would stall on carrering to a traffic ligt or to a easy stop.
Found that the rubber elbow that connects the ISV idle valve to the intake manifold had a small crack.

Stefano

[prj]

Hoses are all Samco and the one from the MAF to Turbo is new and after checking it, it seems fine.

"Checking" is useless.
A boost leak test is done by pressurising the intake with an airline.

Could it not be the Lambda sensor needs cleaning? Oxygen and Mixture problems surely point a bit to this maybe?

Lambda sensors do not need "cleaning". Oxygen and mixture problems are caused in 99% cases by leaks.

It Boosts the same as it's always done, 1.4Bar peak so unless it's peaking just a little too much and I have got a leak, I don't think there is an issue there but I will check.

You might have a leak in the PCV. This will not cause that much issues on WOT, but it will cause lots of issues in the mid-range.

Post a log on hot idle from group 000 in vag-com, this will show most of the issues.

[UrS4boy]

I have also noticed bad idling, Its certainly lumpier than it was a while back before this started. Could it be a plug going down?

I pointed you to this:

Missing and Hesitation Diagnostics:

http://forums.quattroworld.com/s4s6/msgs/22611.phtml

Did you read and act on it?

(Pull the injector electrical connectors one at a time to find the lumpy cylinder and then concentrate on it).

[smogthemog]

Hoses are all Samco and the one from the MAF to Turbo is new and after checking it, it seems fine.
Could it not be the Lambda sensor needs cleaning? Oxygen and Mixture problems surely point a bit to this maybe?
I have also noticed bad idling, Its certainly lumpier than it was a while back before this started. Could it be a plug going down?
It Boosts the same as it's always done, 1.4Bar peak so unless it's peaking just a little too much and I have got a leak, I don't think there is an issue there but I will check.

[rs200]

same fault code I get when maf hose had little crack.. actualy it was boost leak.
missfire can be from bad sparks or coil.

[prj]

Boost leak.

[UrS4boy]

Have a read on this:

Missing and Hesitation Diagnostics:

http://forums.quattroworld.com/s4s6/msgs/22611.phtml

[smogthemog]

I have noticed a slight misfire when accelerating at low revs, seems do it once as if it misses a spark or something. I cleaned my plugs and my G70 but it still does it. I thought it may have been the stupidly hot weather we had a few weeks back but it's still doing it now when the temp has now cooled.
So, I thought I would put the 'tool' on it..... Did this about a week ago and got 00537 and 00561. I reset them but again today checked them and they are back again.

I have looked on the Ross-tech site and know what the both mean - but - could the two be related in any way? Could, say, the Lambda sensor be shot? It's only a cheap one I fitted 40K ago?

00537 = Oxygen Sensor Control
00561 = Mixture Adjustment Control.

Any help appreciated.
Thanks