O2 sensors

sti752 · 02-21-2006, 07:11 PM

Which stock O2 sensor is needed for closed loop functionality? I have an LC-1 ready to go as soon as I receive my downpipe and was just wondering about the stock sensors and their purposes. Thanks.

daemon · 02-22-2006, 06:29 AM

The 02 sensor used for closed loop is the one in the header just before the uppipe. I believe the only purpose of the 02 sensor in the exhaust is to detect bad cats (not 100% sure about this though).

sti752 · 02-22-2006, 08:11 AM

daemon,
thanks for the input but does anybody know for sure? I know the Cobb downpipes come with two bungs, one for WB02 and one for one of the stock O2 sensors. Is that the one that is required for closed loop operation? Anyone? Thanks.

daemon · 02-22-2006, 08:17 AM

I know for sure that the 02 in the exhaust manifold before the upipe is the closed loop sensor. What I'm not 100% sure about is if the only purpose of the 02 past the cat is just to make sure that cats are working. Neither sensor in the the downpipe is for closed loop.

sti752 · 02-22-2006, 08:36 AM

daemon,

oh, I misunderstood you. Sorry about that. Thanks for your help.

daemon · 02-22-2006, 12:18 PM

No problem. I wasn't very clear the first time.

sti752 · 02-22-2006, 04:52 PM

Okay so now that I have that issue understood thanks to daemon. Does any body else know what purpose the O2 sensors in the stock downpipe serve (i'm guessing emissions)?

Also, what downpipes do the rest of you streettuners have and do you have WBO2? For the WBO2 where do you put it and do you keep it in there all the time or just when tuning? Just Curious.

Thanks

daemon · 02-22-2006, 05:06 PM

I have a Cobb downpipe with cat. I use the LM-1 wideband which I put in the bung immediately after the turbo. You don't want to tune off a wideband behind a cat as it will skew your results a little. It can be done, but since you have a pre-cat bung, that's were it should go.

I only have my wideband in when tuning. Mainly because I have that old (e.g. big) Innovative controller box which is annoying. If I had the self contained gauge version I might leave it in. Not sure.

R4ND0M_AX3 · 02-22-2006, 05:57 PM

I have a catless invidia DP. Innovate LC-1 is where the stock rear sensor was. I intend to keep it this way. I use the XD-1 to keep me informed.

02-21-2006, 07:11 PM	#1
sti752 Senior STI Driver Car: 05 Subaru WRX STi Fav Mod: Exige Location: Starkvegas, MS Posts: 379 Join Date: Jul 2005 Trader Rating: (6)	O2 sensors Which stock O2 sensor is needed for closed loop functionality? I have an LC-1 ready to go as soon as I receive my downpipe and was just wondering about the stock sensors and their purposes. Thanks. This ad is not endorsed by this member. Please register or login to hide this ad.

02-22-2006, 05:57 PM	#9
R4ND0M_AX3 Grassroots STI Racer Car: 05 Subaru WRX STi Fav Mod: Cobb StreetTUNER Location: Elk Grove, CA USA Posts: 592 Join Date: Jul 2004 Trader Rating: (0)	I have a catless invidia DP. Innovate LC-1 is where the stock rear sensor was. I intend to keep it this way. I use the XD-1 to keep me informed. This ad is not endorsed by this member. Please register or login to hide this ad.

02-22-2006, 06:29 AM	#2
daemon Professional STI Racer Car: 2004 STi Location: Florida Posts: 806 Join Date: Feb 2004 Trader Rating: (0)	The 02 sensor used for closed loop is the one in the header just before the uppipe. I believe the only purpose of the 02 sensor in the exhaust is to detect bad cats (not 100% sure about this though).

02-22-2006, 08:11 AM	#3
sti752 Senior STI Driver Car: 05 Subaru WRX STi Fav Mod: Exige Location: Starkvegas, MS Posts: 379 Join Date: Jul 2005 Trader Rating: (6)	daemon, thanks for the input but does anybody know for sure? I know the Cobb downpipes come with two bungs, one for WB02 and one for one of the stock O2 sensors. Is that the one that is required for closed loop operation? Anyone? Thanks.

02-22-2006, 08:17 AM	#4
daemon Professional STI Racer Car: 2004 STi Location: Florida Posts: 806 Join Date: Feb 2004 Trader Rating: (0)	I know for sure that the 02 in the exhaust manifold before the upipe is the closed loop sensor. What I'm not 100% sure about is if the only purpose of the 02 past the cat is just to make sure that cats are working. Neither sensor in the the downpipe is for closed loop.

02-22-2006, 08:36 AM	#5
sti752 Senior STI Driver Car: 05 Subaru WRX STi Fav Mod: Exige Location: Starkvegas, MS Posts: 379 Join Date: Jul 2005 Trader Rating: (6)	daemon, oh, I misunderstood you. Sorry about that. Thanks for your help.

02-22-2006, 12:18 PM	#6
daemon Professional STI Racer Car: 2004 STi Location: Florida Posts: 806 Join Date: Feb 2004 Trader Rating: (0)	No problem. I wasn't very clear the first time.

02-22-2006, 04:52 PM	#7
sti752 Senior STI Driver Car: 05 Subaru WRX STi Fav Mod: Exige Location: Starkvegas, MS Posts: 379 Join Date: Jul 2005 Trader Rating: (6)	Okay so now that I have that issue understood thanks to daemon. Does any body else know what purpose the O2 sensors in the stock downpipe serve (i'm guessing emissions)? Also, what downpipes do the rest of you streettuners have and do you have WBO2? For the WBO2 where do you put it and do you keep it in there all the time or just when tuning? Just Curious. Thanks

02-22-2006, 05:06 PM	#8
daemon Professional STI Racer Car: 2004 STi Location: Florida Posts: 806 Join Date: Feb 2004 Trader Rating: (0)	I have a Cobb downpipe with cat. I use the LM-1 wideband which I put in the bung immediately after the turbo. You don't want to tune off a wideband behind a cat as it will skew your results a little. It can be done, but since you have a pre-cat bung, that's were it should go. I only have my wideband in when tuning. Mainly because I have that old (e.g. big) Innovative controller box which is annoying. If I had the self contained gauge version I might leave it in. Not sure.