O2 sensor fooler

[Ross Myers]

>      That's a good question, and I can't argue with you either way. Perhaps
> you can tell me. When I have a scan tool hooked up and floor it, I still
> get a reading and the status does not change to open-loop. I must admit I
> was under the impression the ECM monitored the O2 reading at WOT, and my
> scan tool seemed to bear that out. Am I missing the boat, here? Keep in
> mind this engine is a HO Quad4 from a 1990 Beretta GTZ.
>       Wouldn't it be wise to always monitor the O2 reading...especially at
> WOT?

Absolutely it is a good idea to monitor the O2 at WOT, afterall we 
don't want to run too lean (bang!!). However a wide band O2 sensor 
must be used to get true accuracy. These are a 4 wire sensor that 
also cost several $100 I believe. I'll quote a passage from a Motec 
brochure on their Lambda meter -

"Be Aware!!, Some competitive systems recently realeased onto the 
market utilise the correct sensors and provide resolution to one 
decimal place but do not provide the linearization and temperature 
correction contained in the MoTeC lambda meter. Without temperature 
correction it is common to see errors in the mixture strength of up 
to 1.0 air fuel/ratio. In other words an indicated value of 12.9:1 
would be in the range of 11.9:1 to 13.9:1 in reality, leading to 
either lack of power, poor fuel consumption and poor emissions 
performance or potential engine damage from an overly lean mixture"

Now this MoTeC lambda meter is worth $3,000+ Aus, so given all this, 
do you really feel that your factory O2 sensor & scan tool are giving 
you a "true" indication of mixture strength at WOT?. I'd be 
surprised.

Bye

Ross Myers
Melbourne, Australia