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Dual Narrow Band O2
Posted: Wed Mar 24, 2010 5:57 pm
by ngcontrol
I have a small 90 degree v-twin running on natural gas with microsquirt for sequential fuel and spark. My goal is to minimize emissions and I have installed a catalyst. Currently I am using a single nb O2 sensor that only senses on #1 cylinder, map is on pin 24 green/red, maf on pin 29 orange/green. I also have a pink/black wire labeled MAF that I could not get to work with the maf sensor. I would like to try dual nb O2 sensors and see if that reduces emissions from current setup. Is there a way to connect the second O2 sensor to the leftover MAF pink/black or do I need to use the spare pin 29 orange/green? Also I don't see an Exhaust Oxygen #2 gage in MT, is there a way to display the voltage from the second O2 sensor?
Re: Dual Narrow Band O2
Posted: Wed Mar 24, 2010 7:29 pm
by grippo
The second Ego sensor should be connected to AD6 via Ampseal pin 29. (There is an upgrade code 3.460 which allows you to alternately connect to AD7 via Ampseal pin 5.)
You are right, I don't see an egoV2 gauge. I have put one in the MT2.890 ini file attached. I also added it to the TS 3.460 ini, also attached.
Re: Dual Narrow Band O2
Posted: Mon Mar 29, 2010 4:50 pm
by ngcontrol
Thanks Al,
I wired in the second O2 sensor on pin 29, running MAF only on 24, and with new ini MT now displays both O2 voltages. However I am not getting individual fuel trim. I have dual narrowband selected, but fuel is still controlled by ego voltage #1. Also Pulse Width #2 is approx .25 less than Pulse Width #1, with controller set to single narrowband or dual narrowband.
I will try testing again tomorrow, but any suggestions are appreciated.
Terrific Product!
Thanks Again
Re: Dual Narrow Band O2
Posted: Tue Mar 30, 2010 11:31 am
by grippo
Talk about good timing. I think just yesterday I found a problem that only affected the second of the dual NB sensors. Hopefully the attached code will fix your problem. The ini file is identical to the one for 3.460 that I attached a few posts ago. But note it will only work with TS, so you need to switch to that. Also use the code file in THIS post - only it has the fix.
Re: Dual Narrow Band O2
Posted: Tue Mar 30, 2010 6:13 pm
by ngcontrol
Loaded the new code and switched to TS, all worked perfectly.
Emissions look good, <.5gr/hphr NOX and <2gr/hphr CO at .55 volts for O2 setpoint. I am seeing some extreme fuel trims though, 40% on #1 and 160% on #2. I think my mixer setup is not working properly and #1 is stealing some fuel from #2, playing with injection delay % did not help either. I will try some different injection point/mixer setups and see if that helps.
Thanks again for all the help.