Lambda sensor-easy to take out and inspect and then put back in?

[Jasikasisback]

As my MOT is coming up I want to take a look at the lambda sensor. Is is easy to remove and inspect and then put back without damaging anything? Just wondering as it looks like it is in there quite solid..Reallly I just want to look at it to make sure it isn't all black and clogged and just want to clean it...or is it best to leave it well enough alone...

Any help would be greatly appreciated.

Also what do you guys think about stuff like K-Seal etc....as preventative medicine? (just to avoid having a leak in the future...)

[Gti_Jamo]

From my experience, old lambda sensors never come out easily without the application of a fair amount of heat. Even then sometimes they can still kill the threads on the sensor. If its not broken then I wouldn't touch it. Also with K-seal, if you have no problems then you don't need it. No harm in keeping some in your boot for an emergency.

[Jasikasisback]

i'll leave it for now...

[itavaltalainen]

just read measurement blocks with vcds and see if it works.
or read output with a multimeter or oscilloscope if you have one, no need to take it out for functional check

[Jasikasisback]

i've got a multimeter. what values am i looking for (cold-hot?) dunno even where to begin. got a link or pics to a guide??

[itavaltalainen]

black = signal for ecu
white = 2 x supply voltage for heating
grey (if present) = gnd

measure voltage between the 2 whites, when engine cold this should be near 12V

black to GND should be fluctuating between 0 and 1V - maybe 1 to 2V if it's a newer type with gnd offset (for open loop detection) but don't think that type was used on mk3s

[Jasikasisback]

i've got a plug with a yellow, white, white with a red stripe and orange/brown wire. Am I looking at the wrong plug? I put 2 pics up on flickr.com
account is vwgolfcl1996.

[itavaltalainen]

ah you've still got an original vw one then...

the 'signal' on those is between white and yellow.

heating is white/red and brown wire.

[Jasikasisback]

do i have to have the ignition on for this test?or the car running? i get no reading on the voltmeter

[Jasikasisback]

wires-number 1 on the plug is the red/white pinstripe. number 2 is brown. number 3 is white and number 4 is yellow. i tried 1 and 2 and got no voltage going through it. i've read thet the test has to be done withthe car warmed up at least 10 min so the sensor is functional. I am a total boob when it comes to electronics. i need dummy instructions to do this right....

Found this on another site...


earth brown/black
heater supply red/white
heater earth  white
signal wire yellow