Not sure if this belongs in FI. But being i had my car retuned this weekend, i gotta post because i am BOGGLED. We tuned in open loop mode, everything was good, then after the tune, we set the chip for closed loop mode to utilize the stock o2 again. Only problem is now it seems like theres no reading coming from the stock o2 sensor. I can unplug the stock O2 sensor and NOTHING changes. It still idles like crap. But then when we set it to open loop mode, it idled good and ran fine.. what the hell is up?

 

maybe running the stock O2 un-powered fouled it?

 

Never run and O2 sensor unplugged.

Check the v-out with a volt meter.

 

No, I ran a stock o2 sensor in my exhaust without having it hooked up just to plug my o2 hole because I was running open loop for a while. It still worked after 6 months Sometimes weird stuff like this happens. Not a very good answer but my car in open loop would never idle cold but then when it warmed up it mysteriously would get better as if it went into closed loop.

 

yea i dunno im still really confused. no clue how this is possible. you would think by unplugging the O2 sensor SOMETHING would have changed, but nothing did.

 

is it throwing a o2 sensor cel?

 

no its not. the tuner disabled the O2 sensor heater so it wouldnt throw a CEL. but still the fact that i can remove the o2 sensor and it has no effect on anything blows my mind.

 

Well are you turning the O2 heater back on when you plug the O2 sensor back in?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dustin &raquo;</TD></TR><TR><TD CLASS="quote">Well are you turning the O2 heater back on when you plug the O2 sensor back in?</TD></TR></TABLE>
ding ding ding... beat me to it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dustin &raquo;</TD></TR><TR><TD CLASS="quote">Well are you turning the O2 heater back on when you plug the O2 sensor back in?</TD></TR></TABLE>

no, it is disabled.

 

Well try that. The o2 sensor doesn't give any useful info unless it is hot.