WB O2 location?

[Kckazdude]

I just purchased a WB O2 sensor and am wondering where to mount it. I have read many threads here and elsewhere. Everyone seems to place it from next to the factory NB O2 sensor up to 3' away from the turbo on many applications. What is the best placement for this sensor and why?

 

[jdub]

At least a foot down from the turbo flange, away from the exhaust flame front. Too close and the sensor can be damaged from excessive heat.

 

[grimreaper]

^ agreed 100%, considering most aftermarket gauges sensor are $75+ a pop, id put it downstream. Mine is in the test pipe, you just have to make sure your exhaust has not leaks at any connections before the sensor to have accurate readings

 

[CajunKenny]

Sorry to hijack this thread with this question; but, it is related.

I'm running my WB wires now and am wondering which of my two routes are best.

Route 1: Straight up the firewall on the turbo side and through the main harness grommet. My concern here is heat from the downpipe damaging the wires and/or WB connector.

Route 2: Up over the bell housing/tranny and up the cold side of the engine compartment.

What are your thoughts?

Thanks,
-Kenny

My sensor is mounted toward the end of my DP by the way.

 

[blk92suprat]

Follow the directions for where to mount the sensor....if turbocharged most say at least 36" downstream from the turbo.

Now I've seen some mk3's on here with the wideband o2 sensor right next to the standard o2 sensor...probably wont last to long as these wideband sensors are much more heat sensitive and can be damaged.

To add to the posters questions...is there anything wrong with mounting the 02 sensor after the cat? Whats the reason for the well accepted 36" rule....strictly due to heat temps or is there something else?

 

[Kckazdude]

More questions = more understanding. Hi-jack away.

I was thinking of coming over the bellhousing and going through the firewall with a new grommet. I am using the LC-1 and am not seeing an easy way to protect it from the heat of the turbo/exhaust.

 

[CajunKenny]

Follow the directions for where to mount the sensor....if turbocharged most say at least 36" downstream from the turbo.

Now I've seen some mk3's on here with the wideband o2 sensor right next to the standard o2 sensor...probably wont last to long as these wideband sensors are much more heat sensitive and can be damaged.

To add to the posters questions...is there anything wrong with mounting the 02 sensor after the cat? Whats the reason for the well accepted 36" rule....strictly due to heat temps or is there something else?

My wideband's instructions state to mount it at least 18 inches downstream from the turbo. Mine is mounted approximately 26 inches downstream. So that's not my question.

I'm wondering if the WB wiring will hold up if run up the firewall on the turbo side or if it would survive better up over the tranny and up the firewall on the cold side of the engine bay.

 

[grimreaper]

Ken= id put the cheap wire loom wrap (autozone) on the wire and run it up the firewall along the brake lines (abs system in mind) and see if the wire loom melts or deforms then id run it over the trans or under it if needed.... I guess the different dp we run have different clearances to the firewall so play it by ear man. OTHERWISE you should be fine if things arent melting...

heat kills sensors (o2), so yes, the main reason is heat.

 

[CajunKenny]

Yep, the ABS route is the one I was eyeing up!

Good idea about covering it with loom and monitoring the melt factor of that.

Thanks!

Back under the car I go.....

 

[blk92suprat]

Cajus kenny, my response was to the original thread starter.
I can't comment on whats the best way to wire it since my wideband is sitting in my closet.lol

Just a guess but running it through the hot side to the opening in the cold side firewall might not be a problem..my greddy ebc spec 2 wire runs on the firwall from the hot side to the cold side and I havent had any problems..just an opinion

 

[jdub]

Kenny - Mine follows the harness to the driver's side, then through the firewall. You can run the wire through where the main harness goes through the firewall as well...it will just be a bit more difficult running the wire across inside the dash. Either way works.

 

[tbcmorris]

I run mine towards the end of my DP, I followed the brakes lines across the car and then down. I have not had any issues as of yet. I think your ok as long as your not touching alotough overtime I'd assume heat would make the wires hard.

 

[grimreaper]

jdub hit it i think. Difficult wiring once in the cabin.


Mine runs along the trans (drivers side, sensor in the test pipe) up the intake mani side with some other wires and into the firewall next to the brake booster.

 

[CajunKenny]

blk92suprat: No harm no foul. I actually wondered who you were talking to after I posted. My fault...

Yeah guys, I just came in to take a break before I started throwing wrenches. Not really... But yeah, I am definitely going to run the wires outside. I was wanting to run them inside to keep them in better shape; but, for the amount of work, I'm running them outside!

Plus, I don't think I'd have enough wire to run it inside. It's going to be mounted on the top hole of my pillar pod.

Also, my exhaust doesn't cross to the driver's side until the carrier bearing.

 

[CajunKenny]

Ok guys.

The spot by my brake booster is full already. EGT wires, Power Cable to my amp, Boost gauge lines, etc... No room for my WB gauge wires.

Any other suggestions or should I just drill a hole?

 

[grimreaper]

Ok guys.

The spot by my brake booster is full already. EGT wires, Power Cable to my amp, Boost gauge lines, etc... No room for my WB gauge wires.

Any other suggestions or should I just drill a hole?

drill, carefully. Really no other option i know of