air/fuel sensor range

Hey guys, I have an 08 LGT spec b and I'm getting ready to replace the front air/fuel sensor. The common ones I see are walker and denso. The afr ranges are 12-15 walker and 12-19 denso. Does anyone know the range on the factory sensor? What replacement do you guys use, and also wondering what spark plugs you recommend for a stock LGT??? Thank s for the help guys

Couldn't tell you what the range is but the Denso is likely closer to OE than a walker sensor.

Use stock NGK plugs, the Subaru number is SILFR6A. The over the counter NGK number is LFR6AIX. Gap is .030" Stick with the NGK's.

It sounds like both of those are narrow band sensors so either should be fine for a stock replacement. If you're concerned just get the denso and you get a 4 unit increase in afr range.

i'm talking about the wideband up front and that 4 unit increase is what worries me, there could be a big difference in voltage vs afr. I want to know what the ecu is expecting to see and what the sweep on a factory sensor looks like.
Example: Innovative lc-1 1.56v -12.05 afr 1.72v-12.52 afr
AEM 1.09v -12.10 afr 1.25v-12.50 afr

i have a hard time believing a wideband sensor will only read down to only 12 afr's. from what i've read, most widebands will read from 5-22. i am running low 11 at redline so neither of those sensors would register my car's afr's.

as for the voltage, the o2 sensor should just be sending pulses of 12v power to tell the ecu what the fuel ratio is. i'm not sure what the 1.56v etc. figures you supplied exactly mean.

If this really concerns you maybe you should just get an OE part from Subaru. Keep in mind it's only using the O2 in closed loop.

the voltage values are what the sensor is sending at a given air/fuel ratio. This link was very helpful for testing http://www.motor.com/article.asp?article_ID=977

Oem

thanks for the help guys. I ended up using Denso part #234-9035 (yellow tail) I got it fot 73.86 from theautopartshop