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How do i know if my o2 sensor is working?
I hooked up a multimeter and was reading about 4.5v at idle, close to 5 as i revved it and it dropped almost to zero as i deaccelerated.

Where can i get one if i feel mine isnt doing its job properly? Local parts guy said about $80 for a universal fit one.

well, they are supposed to read betwen 0 and 5 volts, so far so good.

there is such a thng made by ACA called an oxygen sensor tester and is about same price as your O2 sensor !

and someone knowledgable in here says O2 only works on turbos under boost, I know less and sort of doubt the idea due to basic principles of efi ...but....

Dont get too crazy measuring the O2 sensor, I did the same and seen fluctuations etc. I found out later this is normal as the ECU over corrects then under corrects the fuel and ignition etc. They are a narrow band sensor, and only 4 wire ones are more accurate as the are broader band, but need a smarter ECU to calibrate to.

The function of the O2 sensor only really comes into play for coasting or cruising to fine tune the economy, and signal is ignored under boost.

Yours is working fine, leave it, they are a mongrel to remove without the correct socket anyway.

ECU fault codes ? Its generally better to use OEM O2 probes because they are not exactly the same and if the correct feedback signal is not generated the ECU can't give its best results .

Cheers A .

real test would be on an oscilloscope to see the sharpness of changes. the picture loks a bit slanty if slow to read and square if on spec.

My GLTA L series is only single wire btw

22mm ring spanner fits mine and was piss easy to remove - not expected at all!

jono wrote:real test would be on an oscilloscope to see the sharpness of changes. the picture loks a bit slanty if slow to read and square if on spec.

My GLTA L series is only single wire btw

22mm ring spanner fits mine and was piss easy to remove - not expected at all!

yeah the 22mm ring spanner is the key to this part removal, forget it if you don't have one.

I think i'll be replacing my oxy sensor - its still the "old" one from the other engine that died (think its had a lot of coolant and oil fly past it). I only replaced it last year too

And what exactly is a GLTA L series? You've got my attention with this one!

Cheers

even a $5 cheapy 22mm ring spanner does good job

i think Bosch invented the little buggers so one of their aftermarket may just be same as OE?

compare OE to aftermarket price then evaluate ??

GLTA is what Subaru call their, i dunno povertypack/slushbox, RX of the Lseries. It lacks the check interior and charcoal/black interior. Interior of both is brown luxury carpet, brown seats and dash etc. I got a complete 3/87 flapper style AFM and a 85 shell(rolling) They are both brown with red paint outer. both had the air adjustable suspension and stickers on back window to tell the world. Had rear door spats, boot spoiler and turbo 4WD all over the door and bootlid. RX manual VINs were BROBE i think, the auto 3 spd is BROBF I got, and think LTURBOS AWD 4sp electronic auto is BROBF or G. He got a blue interior