O2 sensor bias

[Bruce Plecan]

-----Original Message-----
From: John Wickerham <ibeme at glasscity.net>
To: diy_efi at esl.eng.ohio-state.edu <diy_efi at esl.eng.ohio-state.edu>
Date: Friday, August 28, 1998 9:56 AM
Subject: Re: O2 sensor bias


>I'll add my bit to the discussion about O2 sensor biasing.  I
>have a Chevy S10 Blazer with 4.3 Liter V6, TBI system.  It's
>one of the '7747 ECU's.  I played around with biasing the O2
>sensor high so that the ECU would think the engine was running
>rich when in reality it was not.  The idea was to lean out the
>mix under conditions when the ECU was looking at the O2 sensor.
>
>I know for a fact that as a result of biasing the O2 sensor high
>on this vehicle, that the ECU changed the EGR flow as well
>as the pulse width of the injectors.  If you go too high with
>the bias, the ECU triggers a fault and tells me that the duty
>cycle on the EGR has exceeded 50%.
>
>The point I'm making is that biasing the O2 sensor will do more
>than shorten the pulse width of the injectors.  There may be
>other side effects that negate what you're trying to do.

How were you doing this biasing?.  At some time in the future
might make for a rainy day Bench Project.

Cheers
Bruce
>
>Later,
>John
>
>