I've been getting poor mileage lately and the car hasn't felt as sprightly as it should. So I hooked up my Consult and found that the near-side lambda sensor was 'stuck' at 0.2 volts, reporting a constant lean condition so the ECU was overfueling one bank during closed loop operation. A normal lambda sensor should fluctuate from 0.1v to 0.9v roughly once every 2 seconds on idle.

 

So if you're getting poor mileage and are a bit down on power yet with no DTCs, don't rule out a shonky lambda sensor :thumbup1:

 

I hate OEM lambda control with a passion so rather than bother fitting a new sensor, it's now completely deactivated in my ECU :ninja:

Nice info

 

 

Have some rep :biggrin:

Thats good info.. hooked mine up with Birds conzult the other night and mine shut sit there on take over.

going to get somebody to double check however..

 

how do you bypass them in the ecu? does it not cause any problems? if not why are they there?

unplug it ..

Thats good info.. hooked mine up with Birds conzult the other night and mine shut sit there on take over.

going to get somebody to double check however..

 

how do you bypass them in the ecu? does it not cause any problems? if not why are they there?

 

I've deactivated it by removing the closed loop flags on all the maps. If you simply unplug them, the ECU will throw a code (I've also deactivated the O2 DTC), output voltage will be constantly low (0v) and it will assume you're running lean so you'll run pig rich as a fail-safe.

 

The closed loop parts in the Zed ECU are way too big for my liking, it forces 14.7:1 AFR in the transitional areas where you're coming onto boost, where I richen it up to 13.5-12.5:1. Also, I like to cruise at 15.5-16:1 AFR, but this also means a slower burn rate, so you need a bit more advance to counter this. All in all, it makes the Zed feel a lot more crisp and eager.

Edited September 13, 201213 yr by Noz

if not why are they there?

 

Missed the last part of your post. Lambdas are there to attain a stoichiometric air:fuel ratio of 14.7:1. At this value, all fuel is burnt, which is optimal for catalytic converters which keeps the environment happy.

 

It is possible to run 14.7:1 if you wish without lambda feedback, it just makes tuning a more precise & drawn out exercise (not accounting for the Autotune features present in software nowadays). Some cars I've worked with actually have a more stable AFR this way than when relying on the O2 feedback. I remove it in all my own cars. My Pulsar is amazing on fuel.

Edited September 9, 201213 yr by Noz