Strange looking lambda sensor

[alg]

Just replaced my 3 year old lambda. The old one was dead with one half of the tip coated white and the other half coated brown.
The car has used more oil over the past 6 months. Wonder if dying lambda with overfuelling was causing some bore wash of oil contaminating the lambda (brown) ? We shall see...
The white may well be due to my habit of using silicon spays on the engine bay to protect the tubing. Or did the fitting garage used them whilst fitting ?

Fuel consumption on readout now 20.8mpg (which equals 23mpg when calculated) c/w 15.9 pre change.

Fault code before was max adaptation exceeded only.

Anyway food for thought and given I managed to do this myself nobody should put off replacing a suspect lambda. My advice is to consider it the number one cause of increased fuel consumption and lack of zip on part throttle

[Acidburn]

Might have to give mine a go but from what I recall it was changed just before i got the car and looks new, Gonna check vagcom hopefully this weekend and find out.

[Lloyd]

Fuel consumption on readout now 20.8mpg (which equals 23mpg when calculated) c/w 15.9 pre change.

On what sort of driving Alg? With spirited road (read normal) driving I'm often around the 15mpg. With long distance cruising I can't better 17.3 on the computer which is 22.1 actual.

How much is a new lambda? I'm guessing it may well pay for itself if it can improve mpg!

Are there any other 'minor' components that can be renewed and boost mpg (apart from a block of wood under the loud pedal!)

[alg]

Via Ben @ Listers £68.50 inc VAT/P&P 08456099066 Part no 077906265 Replace it if you do not know when it was last done.

You figures suggest a change. Driving from Yorkshire to Edinburgh 80mph cruise average 21 on display.

Others to consider MAF and coolant temperature sensor at back of block G62 but check them first and/or vagcom for fault codes.

[Lloyd]

Via Ben @ Listers £68.50 inc VAT/P&P 08456099066 Part no 077906265 Replace it if you do not know when it was last done.

You figures suggest a change. Driving from Yorkshire to Edinburgh 80mph cruise average 21 on display.

Others to consider MAF and coolant temperature sensor at back of block G62 but check them first and/or vagcom for fault codes.

Dumb question, but how can the coolant temp sensor affect mpg?

[alg]

If it fails then the ecu uses two failsafe settings based on intake temperature. This can use more fuel if ecu cannot determine correct engine temperature.....

[A80Avant]

i just changed my lambda as well,replacement item has different number than what i had.The one i bought from audi wrote bosch number 0258003994/094 and the replacement writes:0258003957.The only difference i could fins is the cable length which is quite bigger on the replacement part

My symptoms where the dreaded 00561 VAGCOM codes.I used to have after WOT the (MUL) exceeded intermittent and then came in the adaptation mixture not reached.

Only thing i had noticed before was that on part throttle i would feel as the car was not working properly,trying to increace boost but small hesitation.Everything went away though with WOT.
Now after a couple of tests,part throttle was excellent and WOT as well,and some runs i did,didnt bring up the fualt code again.
To get to that though,i replaced the MAF with a new item as well a little while back and also pressure tested the MAF to turbo hose which were able to sustain 0.5bar of pressure quite nice.(i didnt put any more in cause i'd pop one of the bungs again!!!)

i cannot be sure about miles to the gallon or anything since im using larger injectors.

[dan_b]

A failing MAF will definitely kill fuel economy down in to the low teens. It will also manifest itself with a few other symptoms including any of the following:
- you'll possibly feel a hesitation when you jump on the loud pedal, you'll also possibly feel the car hunting by a few mph when its on constant throttle.
- you may notice that you get a sooty exhaust when you give it the full beans and change gear
- you may well start noticing nice popping noises on the over-run from the exhaust.

Lambdas are cheap to source and easy to replace.

[alg]

i just changed my lambda as well,replacement item has different number than what i had.The one i bought from audi wrote bosch number 0258003994/094 and the replacement writes:0258003957.The only difference i could fins is the cable length which is quite bigger on the replacement part

My symptoms where the dreaded 00561 VAGCOM codes.I used to have after WOT the (MUL) exceeded intermittent and then came in the adaptation mixture not reached.

Only thing i had noticed before was that on part throttle i would feel as the car was not working properly,trying to increace boost but small hesitation.Everything went away though with WOT.
Now after a couple of tests,part throttle was excellent and WOT as well,and some runs i did,didnt bring up the fualt code again.
To get to that though,i replaced the MAF with a new item as well a little while back and also pressure tested the MAF to turbo hose which were able to sustain 0.5bar of pressure quite nice.(i didnt put any more in cause i'd pop one of the bungs again!!!)

i cannot be sure about miles to the gallon or anything since im using larger injectors.

Remember WOT takes the lambda out of the equation IIRC

[A80Avant]

oh,didnt know that actually!