02 sensor locations? - The Ford Focus Forum

**marklar34** · 11-04-2009, 11:23 PM

Ok, I'm doing a turbo set-up on my buddys 01' focus. I need to know what you guys did as far as 02 sensor locations. He also has a wideband a/f ratio gauge, so do i need to weld 2 or 3 bungs on the exhaust? Then what is the best location for them? I'm going to weld them in a hour or two, so if anyone can help me out i would really appreciate it!
Thanks in advance!!!!!

**Ja-Red** · 11-04-2009, 11:44 PM

Mine is just be hind the axle behind the motor @ 90deg to the ground. Easy to get to and the cord drops right down off the firewall.

**marklar34** · 11-05-2009, 01:06 AM

Quote:

Originally Posted by Ja-Red

Mine is just be hind the axle behind the motor @ 90deg to the ground. Easy to get to and the cord drops right down off the firewall.

Yeah, that seems like a very good choice. So it sounds like you only have one, and that makes things a little easier. Thanks for the reply!

**hEaT** · 11-05-2009, 07:40 AM

You'll need two or three bungs. Three is the tune still uses the factory secondary o2 sensor. You'll need the primary pre-cat, secondary post-cat and the wideband just before the cat.

If the 2nd o2 is disabled, you'll need both pre-cat with the narrowband being in the factory location and the wideband going as close to the cat as possible without going past it.

If there is no cat, I believe the rule is at least 18" from the turbo. Not sure what it is on a N/A car.

Also, the wideband must be mounted between the 10 and 2 position so moisture doesn't collect.

**pzev04boy** · 11-05-2009, 06:07 PM

You only need 2 since you will have no cat. The sensor with the green connector needs to be used and you will need one for the wideband.

The sensor with the blue connector is the cat monitor and DOES NOT have anything to do with fueling. It is only there to monitor for a functioning catalytic converter. You will need to turn off the rear o2 sensor & heater circuit in the tune to prevent it causing a check engine light.

Stick to about 2 feet after the turbo for the wideband but the factory sensor should be within about a foot or so.

**sofreshsoclean** · 11-07-2009, 01:25 PM

I hate the location of the stock SVT header. my O2 sensor is always getting smashed against my block if I bump the header (lowest part oif the car) so don't put it there.

11-04-2009, 11:23 PM	#1 (permalink)
marklar34 Newbie Join Date: Oct 2009 Posts: 3	02 sensor locations? Ok, I'm doing a turbo set-up on my buddys 01' focus. I need to know what you guys did as far as 02 sensor locations. He also has a wideband a/f ratio gauge, so do i need to weld 2 or 3 bungs on the exhaust? Then what is the best location for them? I'm going to weld them in a hour or two, so if anyone can help me out i would really appreciate it! Thanks in advance!!!!!

11-05-2009, 07:40 AM	#4 (permalink)
hEaT I <3 UC^3 Join Date: Sep 2005 Location: CT Posts: 7,447	Re: 02 sensor locations? You'll need two or three bungs. Three is the tune still uses the factory secondary o2 sensor. You'll need the primary pre-cat, secondary post-cat and the wideband just before the cat. If the 2nd o2 is disabled, you'll need both pre-cat with the narrowband being in the factory location and the wideband going as close to the cat as possible without going past it. If there is no cat, I believe the rule is at least 18" from the turbo. Not sure what it is on a N/A car. Also, the wideband must be mounted between the 10 and 2 position so moisture doesn't collect. __________________ 2001 Twilight Blue ZX3 - Volant Intake, FC 65mm TB, SVT Header, RT High Flow Cat, SVTF Borla Exhaust, Koni's 1985 Nimbus Grey Merkur XR4Ti - Work In Progress Tuned By: Bristol Dyno

11-05-2009, 06:07 PM	#5 (permalink)
pzev04boy Senior TEAM Member Join Date: Sep 2004 Location: Round Lake, IL Posts: 3,192	Re: 02 sensor locations? You only need 2 since you will have no cat. The sensor with the green connector needs to be used and you will need one for the wideband. The sensor with the blue connector is the cat monitor and DOES NOT have anything to do with fueling. It is only there to monitor for a functioning catalytic converter. You will need to turn off the rear o2 sensor & heater circuit in the tune to prevent it causing a check engine light. Stick to about 2 feet after the turbo for the wideband but the factory sensor should be within about a foot or so. __________________ 03 Zetec ATX E&S TURBO SYSTEMS powered sedan 00 Mustang Gt - Built motor - Soon to be Single turbo 07 Ninja 500R Building 640cc race motor.

11-07-2009, 01:25 PM	#6 (permalink)
sofreshsoclean Junior Member Join Date: Jun 2004 Location: Nor Cal Posts: 51	Re: 02 sensor locations? I hate the location of the stock SVT header. my O2 sensor is always getting smashed against my block if I bump the header (lowest part oif the car) so don't put it there. __________________ JRSC BBK with 30lb inj. and matched larger MAF;Mustang coil and 9mm wires to Brisk LGS plugs, SVT header,cat and flex, 2.5"back; SVT airbox n snorcle, K&N panel. ported OEM T.B. ; ERG block off; New MTX trans with Torsen, 6 puck clutch, fidanza flywheel; Urathane rear mount and A "Stiffy" motor snuber. SVT Suspension, FC strut bar, OEM 17 st200 wheels, 4 wheel disc.

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