stock 02 and wideband o2 are so different

[dbaxter_ss]

So why is the stock o2 considered crap?

If its so bad and so far off why hasn't the EPA or some govt agency forced the stock ones to be calibrated or work better?

[Blacky]

The narrow band O2 sensors are *extremely* accurate - but only in a "narrow band" around 14.7 - which is only going to be commanded at part throttle driving (not WOT) which was all the EPA was interested in when OBDII was first mandated. I think now the EPA is pushing for tighter controls at WOT as well, not just at part throttle.

So some mfgs are now using wide band so that they can run 100% closed loop at WOT. I heard a rumour that GM will too - just don't know when.
They are more expensive and require an intelligent controller (i.e. the wide band O2 controllers like LM-1 and PLX etc).

It would make tuning a lot easier.

Also see this post for more info on how the narrow band O2 sensors work
http://www.efilive.com/forum/viewtopic.php?t=1632&highlight=overshoot

Paul

[dbaxter_ss]

Thanks Paul

Thats what wanted to know. Was just working on the GTO wondering WTF do I have a stupid O2 sensor that is not giving me accurate data all the time. NOW it makes sense. Although like most stuff doesn't, you would figure the car makers would have wanted something to know what was going on at all times, just just putting around.

Although I am sure since 99% of the people don't ever use WOT other then to pass trucks on the highway it was not cost effective.

:( Well then, I wasn't planning on getting a wbo2 setup but looks like I will have to. $100 bux at the dyno each time is killing me, and 1 hour is just not enough.

[Scoota]

Derrick, With a WBO2 sensor and the Autotune all set-up, you should have your Dyno time cut down to a quarter of the time.

Cheers, Scotty.

[dbaxter_ss]

I do have a quick question again.

Then why when I am logging with the regular and using equivalence ratio I am showing reading down to 10.5?

This one is showing it down to 12.32...

http://www.purplegto.com/files/eqiv.PNG

[Blacky]

I do have a quick question again.
Then why when I am logging with the regular and using equivalence ratio I am showing reading down to 10.5?
This one is showing it down to 12.32...


Not sure which PID you are logging, but the only AFR data from the PCM is commanded AFR - never measured AFR.
Those values are the AFR tht the PCM is "shooting for". It may or may not achieve them - it depends on many factors, including MAF setup, injector setup, VE table setup etc.

That's why you need a wide band to make sure the PCM is hitting the commanded AFR. If it is not hitting the commanded AFR, then you need to tune the tables until it is.
In fact EFILive's BEN (Base Efficiency Numerator) used in "Autouning" is a ratio of commanded AFR to measured AFR. It generates a very accurate error correction for the VE table.

Regards
Paul

[dbaxter_ss]

AHHH, ok, I thought that is what is was at, not what is was shooting for.

Makes sense.