Afm And/or O2 Problem

[Baconer]

Well this is something thats been happening now and again whenever i drive into Canberra (30 minute drive)

I have an Apexi Pen Turbo Timer so unsure of how precise the readings are but it is fairly consistent in that once car reaches operating temp it reads 20.0 A/F on idle, ~14.7 when driving above 3krpm with O2 doing the usual scanning between 0.2 and 0.7 and going back to .01 on idle but after around 30 minutes of driving the A/F reads 20.0 for a little bit and then just reads '- - -' with a flashing light with the O2 reading 0.01 when driving. Also when it begins doing this if i turn the car off and turn it back on the car nearly stalls...

Fairly certain it is heat related but unsure why it has just decided to start acting this way...

Anyway help/ previous experience with this problem/ ideas on what it could be is greatly appreciated.

[Baconer]

any ideas :X?

[RB20JT]

hey mate,

my mate had the same problem in his sr20, he changed the oxygen sensor....all solved!!

hope that helps

[Baconer]

Thanks, i'll give it a try next time i head into town. Hopefully it works and isnt something more serious

[paulr33]

the pen timer is just looking at voltage and guessing AFR's, its crap and narrowband so dont worry

are you getting resonable economy? how many k's to tank? what ecu (if not stock?) ?

[Baconer]

Stock ECU and getting good kms (always over 550km)

Not taking the turbo timers reading as gospel but more interested in the other problems which occur when it begins reading weird (stalling on startup, losing power, exhaust sounding a lot 'rougher', cant really think of a better way to describe the exhaust note but it is noticeably different)

Car will be put on a Dyno next Saturday so can get a definite on what the AF readings are before it starts acting weird and after, will post up results