Very lean afr and oxy sensor voltage

[wintertidenz]

I fitted a wideband to my car and went for a long trip over the weekend, and noticed a couple of unusual things.

Firstly my afr was around 14.8 to 15.4 cruising and on the street, and at wot it went down to 10.6. When off throttle afr went to free air which doesn't seem right.

On my 100km drive back home today, I noticed on evoscan that my oxy sensor voltage was sitting consistently at 0.77772v but the wideband was still jumping around.

Does this seem to be normal behaviour, or is something not quite right here?

[Kenneth]

That all sounds pretty normal. Were you using wideband to simulate the O2 input? Also, if it was the wideband you bought from me, then average of 15.2 is what I set it at.

Free air on deceleration is also normal. The ECU turns off the injectors to save fuel (since you don't want any power) as as a result you get just air pumping through the engine.

I would be thinking about your evoscan setup, since everything else looks to be normal.

[wintertidenz]

Yes I was using the wideband to simulate oxy sensor input. I initially had problems a while back and completely reset and changed firmware on the wideband I bought from you so it should be set back to 14.7. I will check it out though.

Evoscan is version 2.6 and was left at defaults - I need to upgrade sometime. I logged the entire hour of driving so can provide the logs - only got 1 or 2 knock count on WOT as well.

I used probably 20-25 litres for 230ish km.

[wintertidenz]

Here's the entire log. It's quite long.

Outside temp according to climate control was 20-21 degrees the entire way. Am currently running 600x300x76 intercooler, hard piping from y-pipe post turbo to TB (3" after intercooler, 2.5" pre-intercooler), 3" exhaust and BKR7EIX plugs all round. There is a pod filter, unfortunately directly before the MAF. MAF mod has been done.

The injector scaling was set to 390 on my EvoScan - not sure if that's right.

Was mainly driving at 90-100kph, with some WOT runs when overtaking. First few minutes of logs are when the car was warming up - as can be seen by coolant temps.

[swinks]

Firstly my afr was around 14.8 to 15.4 cruising and on the street, and at wot it went down to 10.6. When off throttle afr went to free air which doesn't seem right.

It does seem very right
It is like should be. Any AFR less than o2 or 22ish:1 and I'd start to worry about dv, stepper motor, boost leak, injectors, etc.

[wintertidenz]

Log wasn't there before - should show now.