hello all,
i have just replaced the lambda sensor on my 1995 wrx,
i connected a volt meter to the signal wire (white) to check it was working ok.
But i found the voltage to be jumping around very fast even once hot,
its going from 0.05-0.94 and all in between vey quickly on idle and under load,
not at any point does it stay around the same voltage
is it right for it to be jumping around this much

 

Hi,
Yeah i have a AFR guage fitted and the only time it is stable is when i am on boost, this is connected to the o2 sensor. I read that this is correct as the air fuel mix is constantly changing under tickover and town driving The voltage is correct, it ranges from 0.1v(very lean) to 0.9v(very rich) iirc Hth.

 

yep, on an oscilloscope the voltage shows a sine wave varying around thos voltage limits

all good

enjoy!

 

thank you for the answers its a great help, when its on full boost (0.9 bar) it hovers around the .9 which i take is right but if i hold it at 0.1-0.2 bar the voltage goes to .00 which i take is very lean befor it climbs back up.

 

Remember that to hold it at 0.1 bar you have barely any throttle opening so the engine does not see that as a high load condition that would need a particularly rich mixture straight away. The important thing is that if you floor it it goes to 0.9 and hovers there which is a good reading.

 

ok thanks, so all is well then, i will go and enjoy