wizardly

Assuming its up to full working temperature, how accurate is the standard lambda sensor readings on the Scoob (3 wire)?

If it is accurate I plan to wire in a digital AFR display for mapping purposes. I'm assuming Ecutek remaps are fueled via standard lambda sensor readings?

Cheers

Bob Rawle

The factory ecu uses the lambda sensor to determine the stoich point for closed loop fueling, this only applies to off boost or cruise conditions within certain limits, all on boost fueling is open loop and not related to the lambda sensor at all. Its accuracy is determined by the conditions of operation and its age, its perfectly possible to map using a narrow band sensor of known condition and output but this entails knowledge and experience.

This applies to the OEM ecu which should not be described as being Ecutek remap, EcuTek provide the software to allow a number of different companies to remap the factory ecu, they are not responsible for the level or quality of remap provided and so the upgrade should not be described in this way.

cheers

bob

dr_ming

The sensor itself is extremely accurate, at any given temperature. The problem is knowing the exact probe temperature. Linear (5-wire) sensors can be configured to have closed loop control of the probe heater, so maintaining an accurate probe tip temperature. This is not possible with switching (3-wire) probes, so the only solution (if you want maximum accuracy) is to measure the exhaust gas temperature by putting a suitable thermocouple into the exhaust, close to the lambda sensor, and using this to control the lambda probe heater current, and hence temperature.

wizardly

I wont claim a great depth of knowledge, certainly not on Imprezas, but do have experience in mapping my own cars in general. I'm gradually developing knowledge on Impreza map targets via this site and 22B.com (slowly)

I think I may have worded that badly. What I meant was I wasn't aware of Ecutek mappers/tuning companies replacing lambda sensors to wideband whilst mapping. Therefore I had guessed that they were mapping on boost fueling with the standard OEM lambda sensors, and merely wanted confirmation of that, so as to conclude whether I could use it for my own mapping.


Cheers, I have an EGT probe within 3" of the lambda sensor which should help, all of this assuming decent lambda sensor integrity.


Cheers for the help so far guys.

WREXY

Most Ecutek mappers started off using the OEM lambda when mapping. Some still use it while others are using wideband sensors now, as they are more accurate. The stock lambda gives lower readings when it heats up.

Cheers,

George.