00561 - Adaptation limit (MUL) not reached - but the car is running rich???

[S2Roo]

My S2 has not been running as it should - the boost does not hold firmly it fluxuates or wavers on WOT. Sometimes it is better than others.

I pulled the following fault code:

00561 - Mixture Adaptation
13-10 - Adaptation Limit (MUL) Not Reached - Intermittent

However I went for my MOT today and the tester said the car was running far too rich - between 300 and 700 CO2.

I have a complete a boost leak test - replaced the MAF and N75.

I am now thinking Lambda sensor - before I spend more money - any previous experience or thoughts on this one??

Thanks in advance.

Andy

[UrS4boy]

...I have a complete a boost leak test - replaced the MAF and N75. ....Andy

Probably wasted your money replacing those two items. Air that has gone past the MAF did not show up in the combustion chamber. The ECU provided the fuel appropriate to the MAF signal but because less air showed up, there is/was over fueling, relative to the air actually present. Not sure if you have completed a boost leak test or not but I suggest that you do one (again, as needed):

S2 3B and ABY (and RS2 ADU) boost leak testing suggestions:

http://www.s2forum.com/forum/showthr...t+leak+testing

[S2Roo]

I have a boost leak test kit and I have tested as you describe but found no leaks....

I'll try again tomorrow just to make sure.

Andy

[UrS4boy]

I have a boost leak test kit and I have tested as you describe but found no leaks.... I'll try again tomorrow just to make sure. Andy

A spray bottle with a soapy solution is your friend. Note the critical leak points, e.g. at discharge from the intercooler where it goes into the cross-member and the hoses around the throttle body and ISV. You probably want to start with Option 1 in the list of testing options.

[Thecrispynoodle]

FPR failing or vacuum leak in attached hoses will cause rich running particularly at idle. Be warned you can end up throwing a lot of money at a 561 code without success. Ask me how I know. My car runs noticeably better than before I replaced various bits and bobs but 561 still recurs. Check for vacuum/boost leaks as per Daves advice and check FPR holds vacuum. If you remove it to test use small amount of Vaseline on the o-ring to get it back in again as its a tight fit and you may damage seal otherwise. Vaseline is petrol based so will dilute and not foul injectors.

[S2Roo]

Thanks for the replies ppl.

Completed another boost leak test and no leaks

I'll try the FPR next.

Andy

[S2Roo]

Okay, the FPR held a vacuum, I replaced the small diameter rubber hose just to be safe. Any other ideas??

Andy

[220bhp]

Possible leak in the crank case ventilation plumbing maybe,or the two one way valves.

[S2Roo]

I have a catch tank system installed so this should not be a problem. I suppose I could double check this by blocking the vent from the catch tank into the turbo feed hose????

[Thecrispynoodle]

As long as crankcase still has somewhere to vent to yes. Is your idle generally stable or does it wander?

[S2Roo]

Idle is stable, crankcase and head vent into a swirl pot and then catch tank so should be okay.

Another thing I have noticed is that when the car has been driven and then left to cool there is a fine oil vapor on the outside of the intake hoses. There is no noticable oil loss on the dipstick - could there be another leak in the oil system somewhere thats allowing oil vapour out and then allowing the catchtank return to the intake to draw extra air in on boost - making the MAF give an incorrect reading????

[UrS4boy]

Do you have a working one-way bleeder valve that prevents boost from going into the crankcase, etc.? Almost sounds like you are blowing oil vapour of the crankcase, e.g. out the dipstick tube (where it meets the block).

[S2Roo]

The catch air return feeds back pre the turbo, so no boost getting into the crankcase.

Tried driving the car with the breather return feed plugged and it has made no difference - back to square one.

Is the lambda even likely to cause this???

Andy

[UrS4boy]

The catch air return feeds back pre the turbo, so no boost getting into the crankcase. Tried driving the car with the breather return feed plugged and it has made no difference - back to square one. Is the lambda even likely to cause this??? Andy

You are not understanding what I am saying about the one-way bleeder valve and boost getting into the PCV system and the crankcase. Nothing to do with the catch can: http://forums.quattroworld.com/s4s6/msgs/22506.phtml

As for the 00561 code, there are lots of possibilities:

•2413 (Blink Fault Code), 00561 VAG1551/2 Fault Code Number
Mixture Adjustment,
Adaptation limit exceeded, Adaptation limit not reached, Leakage in exhaust system before 3 Way catalytic converters, Incorrect signal for Mass Air Flow Sensor, Spark plugs, ignition coil(s), or Ignition Coil Power output stage malfunctioning
Symptom: Rich mixture, increased fuel consumption

[S2Roo]

Thanks for the help UrS4boy.

My swirl pot and catchtank system deletes the PCV system all together - hence no one-way bleeder valve. The crankcase and head vent into the swirl pot - which then drains to sump and also vents to the catch tank. The catch tank then vents directly into the breather connection after the MAF.

Seeing that I have a new MAF and spark plugs I guess I need to test the coils and power output stages. Any tips on those???

Andy