Honda UEGO Sensor...

[Zublin, Bryan (SD-MS)]

>Now, all we need to do is to build a DRIVER circuit
>and we will have the DIY_EFI $200 UEGO sensor...

Jim,
If you have data sheets for this sensor (and maybe an application note), I 
would like to tackle this project.  I have analog design experience as well 
as experience with small embedded controllers.  My approach would be an A/D 
converter with linearization done by the micro.  The calibration table could 
be stored in non-volatile EEPROM.  The parts cost should be less than $50 
($5 for the uC, $1 for EEPROM, $5 for display/driver, $10 for ADC, $3 for 
voltage reference, etc.).  If Honda is putting the electronics in their 
cars, then the interface cost has got to be reasonable.

A few questions:
1.  Is each sensor calibrated with each interface box?  For example, with 
the NTK or Horiba boxes, when you replace the UEGO sensor, do you need to 
recalibrate the unit?  Hopefully the answer is NO.

2.  What kind of accuracy do the manufacturers claim for the sensors?  And 
what accuracy do the interface box manufacturers claim?  This project would 
require the initial accuracy to be decent, without having to calibrate 
(tweak) each unit against an expensive lab standard.

Bryan Zublin
bzublin at gi.com