I hardly ever drive the car on the HWY but today I went on a cruise with fellow Pontiac and Chevrolet owners and most of the cruise was HWY travel.

I am runing the SAUJP code with out the AIR etc. Anyway I noticed something that I wanted to ask to see if this is normal.

I was sitting on 60mph all the time and saw my O2 mV sit on 100-150mv and even to low as 75Mv. It would just sit rock steady around that mark. When I took my foot off the Accelerator the O2 jumped up again and started to fluctuate between 100mv and 900mv (which is normal operation) Then when I accelerated again and sat on 60mph for 30 secs the O2 mV again stayed around the 100mark until I either accelerated or slowed down.

Now has this got something to do with HWY mode? Are the O2 mV supposed to fluctuate also when cruising say at 60mph for longer times or are they supposed to be steady like what I saw today?

Mike

 

What u r seeing is coimpletely normal for highway mode fuel when active(which i believe it is in both saujp versions)

O2 millivolts will drop really low into the 100's and even into double digits................... If (?,?) its setup right and tuned correctly u should see a corresponding drop in inj pulsewidth as well indicating that it is leaning out the fuel mixture

If u do not have highway mode on i would serioulsy start checking things out because either your sensor has gone nuts(o2) or u never datalogged at your mph to invoke highway mode... or your running dongerously lean(not lilkely if u said it drops out when u accelerate)

later
Jeremy

 

Jeremy looks like all is well then was surprised to see the mV that low but all is good ging by what you said.