Ecu Talk / O2 Sensor Help

[910trx]

Already posted in the stickied O2 sensor section however this is rather urgent, hoping on a main page it will get a bit more exposure.

curious

i stuck the cable in the com port of the stagea last night

unfortunately i have not been able to stick the cable in within 60 starts of the lst check engine light so i cant be too sure of the problem.

i'm thinking my o2 sensor is stuffed

the o2 sensor was reading 0.2 to 0.3 V (volts?) on a warm engine after start up

after continuous loops around 2 roundabouts boosting it hard for about 5 mins i returned home

the guage was stationalry, reading 0.02 V

is this a sign that my 02 sensor is shagged?

i'm not sure on what one should read and i dont want to go through the hard slog of country f**k wits to try and get one if its ok.

any ideas of theories?

Reduced: 93% of original size [ 1024 x 640 ] - Click to view full image

[NewKleer]

not sure whats up with ur screenshot, all the sensors there show 0

anyway, 0.3v o2 sensor generally means its dead (assuming its warm). when u rev the engine a bit at idle u should see it move around when engine is warm, if it doesnt react then its dead

best way to tell is log a run and then graph the sensor afterwards (or just look at the readings), it should be moving quite a bit from 0.1v up to 0.9v and back and forth when cruising/light load, and generally moving about to 0.9v on power etc.

[anthonymcgrath]

hiya. I'm pretty sure it should ideally sit at 0.5v which is lambda (14.7:1 ideal afr) and it should periodically flick from 0 to 1. I know its never this exact but 0.2 sounds like its running a spot rich overall (never a bad thing I think personally - much better than the other way around lol!). The fact it doesn't move suggests the o2 sensor may have seen better days and they're not that much to replace so usually worth doing I think if you haven't.

edit sorry its the other way around - 1v is rich, 0v lean - sorry about that!

Edited July 9, 2009 by anthonymcgrath

[NewKleer]

the o2 sensor is a narrowband sensor, which basically means its either reporting 'richer than 14.7:1' or 'leaner than 14.7:1', it doesnt really ever sit on 0.5v but is continually going back and forth as ecu continually fine tunes the fuel around the 14.7:1 point.

so when cruising along, the correct behaviour would not be constant at 0.5v, but rather back and forth from close to 0v and to 1v (even if its reading 0.1v, this may not a whole lot leaner than 14.7:1, and likewise even 0.9v isnt too much richer than 14.7:1)

[910trx]

no the screen shot was after i moved the laptop inside to connect to the net and disconnected from ecu.

i wasn't sure of the scale of the o2 sensor being V (volts i assimed) i wasn't aware it had volts or was supposed to read resistance (ohms), so stuck it up to hopefully trigger someone to look at it.

at the moment on cruise it is sitting at 0.01v to nothing

i'm assuming its dead - casual drivin gets 350km to a 60L tank and would like to see a slight improvement

i just wanted a bit more understanding before i purchase something i may not need

Edited July 10, 2009 by 910trx

[910trx]

repost sorry

Edited July 10, 2009 by 910trx

[NewKleer]

yep if it sits on any single value (but often close to 0v or 0.3v) when car is cruising then its dead. most people dont change them often enough (theyre supposed to be changed like every 40-80'000km i think, but most people are lucky to change them once in the cars lifetime).

[910trx]

thanks i'll look into getting a newie then

ok and love the avatar - its of one of those ACA hoon busts where someone wacked his GF in the drivers seat to save his lisence - hilarious

[NewKleer]

yeah thats it, quite a while ago now i think

[910trx]

that is posted as one of my you tube faves LOL